The ones people have all suggested are good. Another one you might check out is MTurboCompressor. It is basically about 8-10 compressors in 1. A lot of variation available and it sounds good.

Chandler
Another one you might check out is MTurboCompressor. It is basically about 8-10 compressors in 1. A lot of variation available and it sounds good.

This one does look interesting. I'm going to demo it then wait for a sale.
The emulation names are hilarious:
 
Meldy Road
Meve
Meldei 1176
DBMeld 160
Fairmeld
MStressor
Ma2a
MPI-2500
Meldley VariMeld
MSL Buss
 
Too funny! The Melda folks have a sense of humor!
 

BTW, what settings do you recommend for attack and release for subtle master buss compression? the idea is to have subtle gluing effect. I imagine slow/medium attack and the same for release...

I will second the Klanghelm MJUC. It's the most used on my master buss.

http://www.tokyodawn.net/tdr-kotelnikov-ge/
My favorite.

Klanghelm MJUC is great, 3 great compressors in one for very cheap.

attack I personally  prefer 10 ms or just under.....release can imo be anything / depends on the material and tempo.
I try to raise the release to -just before- where it starts to slow down the music.
btw, those are mix settings, I don't know about mastering attack/release

The Slate Buss Compressor pack is fab, as is the UAD 4K Buss Compressor.

Ack!
 
I bought the UAD API 2500 but the UAD-G seems like it might fit my song better. I ain't pay'n $200+ for a plugin though! :) I'm slowly getting the API where I want it. It will make your snare and kick through if you want it to...

I've had Cytomic's The Glue for a couple of years now and I love it. I mainly use the slowest attack, 30ms, especially when there's a strong kick in the mix. I find that even at 10ms, I lose something of the impact of the kick. I also keep the release quite fast. Ratio 2:1 or 4:1 depending on the track. But never more than 2-3dB of GR. 
 
The Glue is awesome on all sorts of material though, I use it on guitars as well.