When I pre-master tracks myself I'll use FabFilter Pro-L @1-3 db reduction on pop/rock material. I find very transparent for most material, sometimes Slate's FG-X for louder rms masters.
Here's a freebie; Limiter No.6
http://vladgsound.wordpress.com/plugins/limiter6/ 
Tonebooster's Barricade; Voxengo Elephant, PSP Xenon.
Always best to demo if you can to see what suits your music or taste..

Hi all, i use Voxengo Elephant and other many plugs in different session on 32bit 48000 export file. A question for you.I have just seen AOM Invisible Limiter,is a Pro Japan development.The comparison file (i hope that is true!)is amazing. Do you know this stuff???Best

For Limiter, I use the Concrete Limiter.  I also use the 4K Bus Comp.

Concrete Limiter.

scook


FabFilter Pro-L

+1.

T-Racks3 Brickwall Limiter

I like the T-racks limiter and also I have the Flux Pure limiter...But I usually use the T-racks.

i still use boost11 sometimes.

Concrete Limiter on my master.

I use the Waves L3-16, almost exclusively these days as my brickwall. I try others when I find them, and there are a great selection of well-made tools but the L316 has some really powerful ways of limiting with a Priority curve and some great Release Character settings (Warm Analog is my fav). Now, it's not the only tool I master in the box with, but it is always the very last thing in the chain.