Anas bin Malik رضي الله عنه narrated that : the Messenger of Allah صلى الله عليه و سلم said:
“Whoever prays Fajr in congregation, then sits remembering Allah until the sun has risen, then he prays two Rak’ah, then for him is the reward like that of a Hajj and Umrah.”
He said: “The Messenger of Allah صلى الله عليه و سلم said:
‘Complete, complete, complete.'”
Jami` at-Tirmidhi 586. Classed it as hasan by Shyakh al-Albaani in Saheeh Sunan al-Tirmidhi.
Abu Umaamah (radiya Allaahu ‘anh) related that the Prophet (sall Allaahu ‘alayhi wa sallam) said :
“Each of [the following] three has a guarantee with Allâh – that if he lives, he is taken care of , and if he dies, he will enter Paradise: One who enters his house with ‘Salaam’ has a guarantee with Allâh ‘Azza Wa-Jall (The Most Mighty and Exalted); One who goes out to the Masjid has a guarantee with Allâh; and One who geos out in the way of Allâh has a guarantee with Allâh.” 
 Al-Adab Al-Mufrad (1094). Al-Albaanee said, “Saheeh.”
Abu Hurairah (May Allah be pleased with him) reported: The Messenger of Allah (sallallaahu ’alayhi wa sallam) said, “Everyone among you will be deemed to be occupied in Salat (prayer) constantly so long as Salat (the prayer) detains him (from worldly concerns), and nothing prevents him from returning to his family but Salat.”
[Al-Bukhari and Muslim].
Commentary: This Hadith tells us the merits of waiting for Salat. As long as a person sits in mosque waiting for Salat, all his time is reckoned as being in the state of Salat and so eligible for the same reward.
Anas (May Allah be pleased with him) reported: Once the Messenger of Allah (sallallaahu ’alayhi wa sallam) delayed the night prayer (`Isha’) till midnight. He (sallallaahu ’alayhi wa sallam) turned to us after Salat (prayer) and said, “The people slept after performing their Salat, but you who waited, will be accounted as engaged in Salat throughout the period of your waiting.”
Posted from : Imam Al-Nawawi’s Riyad-us-Saliheen, Chapter 190, The Excellence of waiting for As-Salat (The Prayer) , Published by Dar-us-Salam .
On the authority of Abu Dharr (radiAllahu anhu), that the Prophet (sallAllahu alayhi wasallam) said –
“Whoever says ten times immediately after finishing the Fajr (Dawn) Payer, before moving from his place or talking to anyone,
“laa ilaaha illallaahu wahdahu laa shareeka lahu, lahul mulku wa lahul hamdu yuhyee wa yumeetu wa huwa alaa kulli shay’in qadeer – [ none has the right to be worshipped except Allaah alone having no partner, sovereignty is His and all praise is for Him and He brings life and He causes death and He has full power over everything,]”
ten good deeds will be recorded for him, ten sins will be eliminated from him, he will be upgraded ten degrees (in reward), he will be safeguarded from all kinds of harm all that day, he will be guarded against shaytan and no sin can overtake him on that day (and nullify his good deeds) except associating others in worship with Allaah. (At Tirmidhi no.3484 [5/515])
At-Tirmidhi commented on this hadeeth saying, “This is a hasan, saheeh hadeeth (i.e a good and authentic hadeeth)”.
Likewise it is an act of Sunnah to say dhikr ten times straight after Magrib salah too, according to a hadith related by Imaam Ahmad Hanbal (rahimahullah) on the authority of Umm Salamah (radiAllahu anha), hadith number 26430. Also stated in Sahih Ibn Hibban no. 2023.
Source : A Summary of Islamic Jurisprudence – Dr. Salih al-Fawzaan, Volume 1 , Chapter 10
Here is an excerpt from Ibnul Qayyim (rahimahullaah):
There is an hour of acceptance, and it is the hour in which no Muslim happens to supplicate to Allah for something except that it will be given to him. In the hadeeth reported by al-Bukharee and Muslim on the authority of Abu Hurayrah that Allaah’s Messenger (salallaahu ‘alayhi wa sallam) said:
Indeed, there is an hour (opportune time) on Friday and if a Muslim gets it while praying and asks something from Allah, then Allah will definitely meet his demand. And he (salallaahu ‘alayhi wa sallam) pointed out the shortness of that time with his hands.
Translated by brother Salah al-Iranee
From Aboo Hurairah – radiyallaahi ‘anhu – who said: Allaah’s Messenger – salallaahu ‘alayhi wa sallam – said:
<<Among the deeds and virtues whose reward will reach the Believer after his death are: knowledge that he taught and disseminated; a righteous son whom he left behind; a written copy of the Qur`aan which he left as a legacy; or a mosque that he built; or a house that he built for the passing traveller; or a canal which he dug and caused to flow; or charity which he gave from his property whilst he was alive and well, for which he will continue to receive reward after his death.>>
Reported by Ibn Maajah (no.242), Ibn Khuzaymah (4/121/2490), and al-Bayhaqee in Shu`abul-Eemaan (3/274/3448). Declared ‘hasan’ by Shaikh al-Albaanee in Saheehut- Targheeb wat-Tarheeb (no.77).
Source: http://alitisaambissunnah.wordpress.com (It has Arabic text of hadeeth as well)
Aboo Dawood (rahimahullaah) reported (no. 345) from Aws ibn Aws ath-Thaqafee (radiallaahu ‘anhu): I heard Allaah’s Messenger (salallaahu ‘alaihi wa sallam) say:
“Whoever washes his head on the day of Jumu’ah, and takes a bath and arrives in time, and he walks and he does not ride, and he draws close to the imaam, and he listens and he does not speak. Then for every step which he takes, there will be for him the reward of a year: the reward of fasting it and standing in Prayer.”
Shaikh al-Albaanee (rahimahullaah) said this hadeeth is (saheeh) authentic.
Further Reading :
Abu Hurayra reported that the Messenger of Allah, (may Allah bless him and grant him peace) said, “And if they only knew what was in the prayers of ‘Isha’ and Subh [Fajr], they would come to them even if they had to crawl.” [Al-Bukhari & Muslim]
`Uthman bin `Affan (May Allah be pleased with him) reported: I heard the Messenger of Allah (may Allah bless him and grant him peace) saying, “One who performs `Isha’ prayer in congregation, is as if he has performed Salat for half of the night. And one who performs the Fajr prayer in congregation, is as if he has performed Salat the whole night.” [Muslim]
Abu Hurairah (May Allah be pleased with him) reported: The Messenger of Allah (may Allah bless him and grant him peace) said, “No Salat is more burdensome to the hypocrites than the Fajr (dawn) prayer and the `Isha’ (night) prayer; and if they knew their merits, they would come to them even if they had to crawl to do so.” [Al-Bukhari & Muslim].
[Translated by Aboo Talhah Daawood ibn Ronald Burbank]
Source : www.alitisaambissunnah.wordpress.com
At-Tirmidhee reported in his ‘Sunan’ [Kitaab Tafseeril-Qur.aan: Chapter (39): And from Soorah ‘Saad’ (no. 3233)]:
“Salamah ibn Shabeeb narrated to us, and `Abd ibn Humayd, both saying: `Abdur Razzaaq narrated to us: from Ma`mar: from Ayyoob: from Aboo Qilaabah: from Ibn `Abbaas who said: Allaah’s Messenger said:
<< Last night my Lord -the Exalted and Most High- came to me in the finest form >>
he said: I think he said: << in a dream >>,
<< so He said: ‘O Muhammad! Do you know what the highest company (of Angels) are disputing about?.’
He said: “I said: No.”
He said: So He placed His Hand between my shoulder-blades, so that I felt its coolness within my breast – or he said – my chest. So I knew what was in the heavens and upon the earth.
He said: ‘O Muhammad! Do you know what the highest company (of Angels) are disputing about?’
I said: Yes, about those things which efface sins; and those things which efface sins are:
Remaining in the mosques after the Prayer, and walking upon foot to the congregational Prayers, and perfecting the wudoo when it is difficult.
Whoever does that will live upon good and die upon good, and with regard to his sins he will be like the day his mother gave birth to him.”
He said ‘O Muhammad! When you pray then say:
Allaahumma innee as aluka fi’alal khayraathi, wa tarkil munkaraati, wa hubbaal masaakeeni, wa idhaa ardatha bi ibaadika fitnatan faqbidhnee ilayka ghayra maftoon
O Allaah, I ask You for the performance of good deeds, and the abandonment of evil deeds, and for love of the poor and needy; and if You wish to put Your servants to trial then take me to Yourself (in death) not being put to trial.’
And the (high) levels are propagating the greeting of ‘Salaam’, providing food, and praying during the night whilst the people are sleeping. >>“
[Shaikh al-Albaanee said: ‘Saheeh’ ]
Abu Hurairah (May Allah be pleased with him)reported:
The Messenger of Allah (Peace be upon him) said, “If they knew the merits of Salat after nightfall (`Isha’) and the morning (Fajr) Salat, they would come to them even if they had to crawl to do so.”
[Al-Bukhari and Muslim]