Well so far I have the doubler which is great and a duende 1.5 with the eq and dynamics. I can't run this until mellowmuse ata bring out their rtas version though. I'll look into all the other one's you guys mentioned though.
RenEQ and RenComp are workhorses that always sound good to me. Anyone looking to get their feet wet in the Waves world without too big an up front commitment should look at the RenMaxx package, which includes all the Ren plugs plus the IRL and a couple others. It's a great value.
I have the Platinum, and to me that's the sweet spot. You get the most functionality for the best price there. Moving up from there you get some cool stuff but as with all things the cost goes up fast relative to the extra functionality.
IR-L is quite nice and I use it on every project as well as SuperTap and the doubler (as a harmonizer.) C1/Q10 still have their place if you want something cleaner sounding (the Ren stuff has a more vintage vibe.) C4 is a really nice multi-band, and L1, L2, and LL3 are all very useful. Enigma can be used for some cool stuff as well. For mastering there's the Phase Linear stuff.
If you have IR-L, be sure to spend the $10 and get the two DVDs of impulse files. It makes all the difference to have plenty of really high quality (24/96) IR files to select from.
The SSL/API stuff, as mentioned, is some of the best stuff out there today. For aggressive drums, the SSL is pretty awesome. For more laid drums I'd use RenComp/RenEQ instead. I demo'd the API and it's great and I'll get it when possible.
I always find myself coming back to the Ren comp and EQ. Yeh, the SSL bus comp sounds nice, but throw RenComp on the master bus with the right settings and it's may sound even better. For syrupy/slinky guitars, the comp in Opto/Warm mode is really nice.
Waves v series and ssl do it for me. Esp ssl eq.
Never got the hang of the API compressor for some reason.
Still use the Rcomp for vocals now and again.
Z noise can be a life saver.
Q10 for surgical (but I prefer Sonalksis - adjustable slopes)
I only own the SSL collection, but I have tried the API and the API 2500 compressor is great. Also the V-series is great too and I thought the VEQ4 sounded good. Out of all of the Waves plug-ins I have tried the SSL is on my "must have" list.
The whole Renaissance collection are staples (RComp and the 4 band EQ in particular), as are L2, IR verb, and a few others...I even bust out the C1 comp here and there just so i'm not always using the same compressor. Supertap delay is handy if you need something to a specific tempo, and if you're doing any remastering of older stuff, the Restoration stuff is unreal.
I have the Platinum bundle and the V-Series. I mostly use the Renn stuff but also Metaflanger, L2 and L3. Overall I'm happy with them! The V-Series is what stands out though, at least for me. Highly recommended!
I haven't upgraded my WUP yet but will do so. I think it's fairly reasonable now, with no accelerating fees if you don't renew it and the fact that your license is safe, should your iLok dissapear or break. The platinum bundle has also been upgraded with four new plugins, so I think it's worth the cost actually. At least this time around..