For the record, I've been using Reaper for about two years now, and have been very happy with it. I personally find its MIDI editing is kinda clumsy, though, so if that's important to you, take that into consideration. In the end, though, I don't do enough with MIDI for that to matter, as everything else about the program is excellent.
As for plugins, I have been making my first album using nothing but free plugins and what comes with Reaper. The vast majority of all the others I use are from Variety of Sound:http://varietyofsound.wordpress.com/
NastyDLA is the closest I've ever heard to a real tape loop delay in the digital domain. I haven't heard them all, though, so that opinion may vary, but for the price, it can't be beat.
ThrillSeekerLA is my go-to track compressor for just about everything except drums, for which I reach for DensityMkII, also from VoS. And I just noticed that DensityMkIII is out now. Time to go read up on the differences.
Getting away from VoS, there's the PushTec EQ from LeftoverLasagna: http://www.leftoverlasagne.com/leftoverlasagne/plug-ins.html
. They're a graphic design company making GUIs for other plugin companies, as far as I can tell, but their one sample offering is actually pretty good.
Finally, I really like Reaper's own ReaEQ for the transparent, surgical stuff. If you don't use Reaper, you can download the ReaPlugs package here for any Windows host that supports VST: http://www.reaper.fm/reaplugs/