Recently I've gone back to firefox (8, nightly) because of two issues with chrome: memory usage and constant crashes (as of lately, on a mac).

I must say that, although I'm a tab freak (I always have around 30 to 50 tabs and/or windows opened at the same time) it is very fast and never uses more than 500mb of ram.

The only issue that I have is that it doesn't play well with rescuetime. Other than that, a delight.