What's your favorite foundation?

I have been doing some research on foundations for quite awhile (basically since I started wearing makeup...some 20 years ago?!). I have yet to find the "perfect" one, but some are pretty good: Paula Dorf Perfect Glo (read review below), Bloom Foundation (I use #2), Neutrogena, Clinique...I literally could go on and on.

I keep hearing about Chantecaille and I really want to try NARS, but living in the middle of the country with few cosmetics counters to actually check out these expensive little gems before dropping upwards of $50...long whining complaint short, I need help.

Here's where I request your input: What is your favorite foundation? And why do you love it?