I agree about getting a wee tester bottle, I seem to have bought a differnt foundation every 6 months for the last few years and I haven't bought the same one twice.
I have tried two different Lancome, colour ideal is my most recent one, I am not keen on it, I find it thin, quite drying almost powdery and quite perfumed.
The other one was a compact, it was okay.
I have used clinique, but I wouldn't rave about it.
I like the benefit palette I bought, it has a great "industrial strength" concealer in it, that really works, called Boing (I think) I like it so much I am thinking of trying a Benefit foundation.
Also tried Nvey or some such organic one, it reminds me a lot of the Lancome. (though it was cheaper)
Cheap foundation I have used recently - Revlon Beyond Natural "skin matching make up" - it comes out a grainy white and blends into your skin tone - it is okay for such a cheap foundation, though it doesn't last all day!
I am 36, with okay skin, which can tend towards being dry, not oily.