My $0.02
Based on the current prices on Sweetwater.com and my experience/exposure with each of the following, I'd rate them as follows in order of realism and capability. Notice how the price goes up as does the realism/control.... the exception being BFD 2.
Toontrack EZdrummer $149.97 ( Expansions are roughly $80 each and somewhat worth it )
Definitely EZ, sounds great but very limited sound shaping/control without using extra/outboard plug-ins. With enough outboard work it can sound awesome but that's not why you buy EZ Drummer.
XLN Audio Addictive Drums $229.97
EZ as EZ Drummer and way more sound shaping/control built in. Sounds great out of the box, even better if you know how to tweak it. Does Metal and old school rock/blues all with ease.
--------- Here's where it gets out of hand -----------
You really need to know hwat you're doing to get the most out of these more expensive ones.
FXpansion BFD 2.0 $399.99 ( Without the Steve Slate samples @ $329.97, definitely behind Superior 2 )
Awesome but only with lots of tweaking, expansions/add-ons and outboard plug-ins.
Toontrack Superior Drummer 2.0 $299.97
Awesome sound shaping/control built in. Sounds great out of the box, unmatched if you know how to tweak it.
The lack of sound quality/realism/intuitive interface has left Guru, Storm Drum,
DrumCore,
Percussive Adventures 2, Session Drummer 2,
Kinetic 2 off my list to consider. Also, I am not a fan of loops at all. Your control is very limited with them. I've not tried
YellowTools Culture though I've heard good things about it.
Haven't tried M-Audio Drum and Bass Rig, Stylus RMX, Sonic Reality, East West or ILIO at all.