2 tables for me. 3 is too many for my connection, things get too slow. I'll play 2 rings or throw in a SNG. Or if i'm in a MTT i'll open a cash game.

Playing more than one table is better for me because it is much easier to be patient and tight by seeing twice the hands. If you play with tables windowed you can pretty much see all the action at both tables and not miss anything.

The only problem is that when I play live at only one table, I find myself getting bored.