BetOnLine is a good one.
El Dorado's poker
is pretty low-key and the software is fine, but they are not known for paying well, I think.
I also play at Intertops
and like their software, but not too sure about them paying out well lately.
Tux has good software and plenty of low cost tourneys if the winner wants to play more tourneys with their money.
And as I said in the other thread, I am good with any of them. And of course I am thinking you need to pick one with a good offer as far as "shelling out" for a Freeroll.