Me and my brother used to watch these almost every day. Good times. Some of the performances I know by heart. (One forom Chicago, WOWY on Rattle and Hum, both encores on Rose Bowl,...) <3
Chicago, simply because it's the first U2 DVD I purchased and I really liked the footage and the set.
But the video segment from any of U2's DVDs that I watch the most is Bad/Where The Streets Have No Name from Boston. When people ask why I love U2 so much, that's the video I point them to.