RNC gets my vote for no colouring, and affordability. (I can't afford an Avalon quite yet, but used it in a friend's studio and it is lush.)
Have used DBX 286A and got LOADS of colour. Joe Meek definitely colours lots, good for doing a single vocal take, but I wouldn't use it on BVs. 
er... that's it.
any opinions on the FMR Really Nice Levelling Amplifier???