The Best of the X-Division Vol. 1 has alot of great matches on it. If you can find the original Best of the X-Division DVD, which highlights the first two years of the division, it is also packed full of great matches.
I would also suggest the DVDs that focus solely on a particular talent like Phenomenal: The Best of A.J. Styles, Heaven Sent, Hell Bound: The Best of Christopher Daniels, Nevermore: The Best of Raven, and the upcoming Unstoppable: The Best of Samoa Joe.
You really can't go wrong with any of the above DVDs. Each promises you atleast one Match of the Year candidate and plenty of other great matches.
Speaking of the Daniels DVD - is it a clipjob? Or are all the matches listed on the back presented in full length?