"Bargain" brands are an invitation to disaster. Sometimes even reputedly "good" brands can be problematic as Canon techs have advised some owners with problems to use SanDisk Extreme III Class (6), saying the Canon cameras can be a bit "brand picky".
One T1i owner (same minimum specs on cards stated in the manual as for the T2i) was losing video as his camera literally "shut down" video recording in the middle of a shot. He was seeing a buffer bar appear, fill up, and then the record mode would shut down.
This guy was using Kingston brand 16GB Class (6) cards - he had two - and thinking they might be defective he bought another. Same story.
Canon advised SanDisk Extreme III Class (6), he bought one and his problem went away.
SanDisk Class (6) are getting a bit hard to find, but Class (10) are plentiful and work just fine. That's what I use.