Well a lot of the "usuals" are carried over from hype on the internet and among engineers. You definitely don't "need" waves and such these days if you are good about working on your source.
The reality is that everybody has preferences. So there is really no way to do this until you do the tests yourself and learn the character of every plug or piece of hardware. That's why every plugin maker has demos and hardware has return policies. There is just no way to know.
On the cheap (or not) I can't say enough great things about Stillwell plugins. They are very affordable and right up there with anything out there. Voxengo's stuff is some of the best and affordable as well.
But there are TONS of free offerings these days. Bootsie (variety of sound) stuff is excellent. Kjaerhus classic series stuff I use all the time. Digitalfishphones blockfish and endophin are excellent. I use dominion all the time. Gvst's stuff is good too.
As a "goto" compressor I like something clean first. I don't like an 1176-esque or Distressor-esqe sound on most things and you really to use one to know what I mean. Also I don't crush drum busses enough to bring out that extra color anyway. Just enough to bring out more room or more punch. But look that the Reaper plugins too, Reacomp is very good. Also the EQ is good too. Or even built-in stuff, at least give it a try. I find myself using Cubase's built in stuff more and more. Low CPU usage, clean, and just does what it is supposed to.
Also every source is different. Over time I have learned how to listen or run a new plug or hardware through its paces, make a mental note of its characteristics and then remember when I think it will apply to a source. And I rarely pick it the first time, but these days I don't get much beyond 3 tries. All depends on the mix. But with good sources, you just want to control dynamics really.
You just have to try and listen for yourself. But really focus on your source first and it won't matter much really. I have heard lots of pro and well selling albums that used all stock plugins, but good sources.... and most importantly... good songs.
