I agree that the Line 6 stuff is the best in this department in my experience. I use all individual pedals, but for recording I really like the M series stuff along with the XT live.

I have not had much experience with TC Electronics outside of seeing the vocal effects in use, but I know several people that love that stuff. Yes, steer clear of too much "amp modeling." The amp modeling can really change the tone and when you want just effects, that can be a burden. Also, some effects processors (particularly the BOSS GT stuff) get way too in depth and even the simplest things can be overly complicated.

Here is a link to the Line 6 M13 and M9, which I think both are great.
http://line6.com/m9/
http://line6.com/m13/

- Douglas