I used to use tube amps always.
Marshalls...Laney's...Boogie.
The last few years I've owned a Marshall Valvestate and currently a transistor B52.(they also make tube amps).
I need a totally clean channel for my modeling effect and a tube amp always colours the clean channel too much for my liking.
Adrian Belew does a similar thing in that he uses the clean channel and adds his effects to it....nothing like having a clean palet from which to start.