depends on the spends - i use sonalksis comp - its very nice - there TDK filter is a nice bit of kit too - i use oxford eq (like that alot) and effex the d16 devestor. those are the only treats i could afford - the rest i use come with ableton or freeware
mind found some good freeware - audio damage rough rider is a nice comp (i like it for kicks and snares) a nice delay imo is TAL audio dub delay