Prayer in Congregation (Jamat) is 27 Times Superior

[Sahih Bukhari: Volume 1, Book 11, Number 618]

Narrated 'Abdullah bin Umar (Radi Allah Anhu): Allah's Apostle (sal-allahu-alleihi-wasallam) said, "The prayer in congregation is twenty seven times superior to the prayer offered by person alone."

[Sahih Bukhari: Volume 1, Book 11, Number 620]

Narrated Abu Huraira (Radi Allah Anhu): Allah's Apostle (sal-allahu-alleihi-wasallam) said, "'The reward of a prayer in congregation is twenty five times greater than that of a prayer offered by a person alone. The angels of the night and the angels of the day gather at the time of Fajr prayer.' “Abu Huraira then added, "Recite the Holy Book if you wish, for "Indeed, the recitation of the Qur'an in the early dawn (Fajr prayer) is ever witnessed."

[Sahih Bukhari: Volume 1, Book 11, Number 626]
Narrated Abu Huraira (Radi Allah Anhu): The Prophet (sal-allahu-alleihi-wasallam) said, "No prayer is harder for the hypocrites than the Fajr and the 'Isha' prayers and if they knew the reward for these prayers at their respective times, they would certainly present themselves (in the masjids) even if they had to crawl."

[Sahih Bukhari: Volume 1, Book 11, Number 631]

Narrated Abu Huraira (Radi Allah Anhu): The Prophet (sal-allahu-alleihi-wasallam) said, "Allah will prepare for him who goes to the masjid (every) morning and in the afternoon (for the congregational prayer) an honorable place in Paradise with good hospitality for (what he has done) every morning and afternoon goings

Rasul Allah (sal Allahu alaihi wa sallam) said: “The person who joins the Jamaat for prayer at the start i.e. first Takbeer, for forty days at a stretch is secured from the torments of Jahannum as well as from the evil of discord.” [Tirmidhi]

It is narrated by Abdullah ibn masood (ra) that:
“We saw that only the hypocrites left the jamaat and by doing so we considered that person to be a hypocrite. Or those people who were sick. Verily a sick person would come walking to the masjid in-between two others who would help carrying him. And he said: verily the Holy Prophet (sallallahu alaihi wasallam) taught us the sunnah and right guidance, and among the sunnah and right guidance is salaat in the masjid which there was an azan.