Check Rob Galbraith's CF database:

http://www.robgalbraith.com/bins/mul...?cid=6007-6425

...hopefully that links to it. The Lexar 80x is rated "best" but look at the margins...the Rebel will not do justice to the 80x for its price. It's up to you, but when I had the Rebel I bought a 1 G "standard" Sandisk and also an 256 MB "Ultra II" Sandisk and for the life of me could not tell the difference in typical shooting. With the 20D it's a different story, though.