1) ValhallaFreqEcho - don't use the shift function at all really but great delay that I use a lot.

http://www.valhalladsp.com/valhallafreqecho

2) W1 limiter  - I have the L1 from waves but has been useful when I forgot my waves key! great clone.

http://www.yohng.com/software/w1limit.html

3) Span Voxengo - Gets used in every project - super useful!

https://www.voxengo.com/product/span/

I also really like variety of sound stuff - (bootsy) all really good

http://varietyofsound.wordpress.com/

My top 3 have already been mentioned.

1 Melda Free Effects Bundle

http://www.meldaproduction.com/plugins/product.php?id=MFreeEffectsBundle

2 Blue Cat Bundle

http://www.bluecataudio.com/Products/Bundle_FreewarePack/

3 Variety of Sound

http://varietyofsound.wordpress.com/vst-effects/

There are a few I have not seen mentioned yet so here is my list of free VST effects, amp modlers, and synths

http://marcuscurtismusic.com/2013/03/07/building-a-home-recording-studio-part-5/

Sonar X2 professional really has everything you need. If someone has Sonar essentials or Sonar studio then some of these may come in handy. Personally I just like having more toys in my toy box and free is a good thing!

My top pick is the Melda bundle

Alchemy Player
Valhalla Room (not free ~$50, but awesome).

Dave