What sim / impulse combination you guys prefer for stoner / doom type guitarsound, Sleep, High on Fire, YOB, Black Sabbath for example? I've been using HyBrit with ReCabinet 2.1 1960 impulses, but I'm not perfectly happy.
Shitty youtube quality on some but you get the idea
For amp sims you might want to try these,
Aradaz Amp 2 Green
http://aradaz.blogspot.com/2008/06/aradaz-amp-2-green-release.html
and BTE's Juicy 77
http://www.bteaudio.com/software/Juicy77/Juicy77.html
I found these two amp sims respond very nicely to KaltHallen Studio's T75 cab sims,
http://www.guitarampmodeling.com/viewtopic.php?f=32&t=15844
and with Let it burn's Orange 4x12 v30 impulses
http://www.ultimatemetal.com/forum/equipment/376985-my-orange-4x12-v30-impulses.html
I've been able to achieve some very nice vintage sounding tones using various combinations of these amps and cabs
Also, try KeFIR as your impulse loader. For some reason I get much better results using it than I do with LeCab.