Cock size matters a lot to me when watching a girl get fucked, it pretty much needs to be way bigger than mine. there are a lot of girls in the industry who clearly go for big sizes and it's nice to see them get beyond satisfied.
To me there are six guys, only counting guys who work frequently still, who stand out the most as beyond big even by porn standards. Their cocks get a lot of comments from the girls (beyond the usual). All of these guys have girth, there are plenty of dicks in the industry that are long but not especially thick.
Here they are, not really in order.
Mike Adriano - not the longest but maybe the girthiest on this list or at least top 2-3. His style is not for everyone, neither is his dick, but a lot of the girls say he is the best.
Manuel Ferrara - dude is straight hung, I think everyone can see that
Chris Strokes - not totally sure how thick he is compared to others on this list, but easily above average girth and extreme length also
Sean Lawless - the head on his cock is seriously unreal. not as much history as others on this list but burst on to the scene in a big way
Bruce Venture - if I would kick one off the list it is this one because it doesn't always get as hard, but it does sometimes.
Danny D - I think probably the biggest overall white guy in porn. Maybe girthier than Mike and almost as long or longer than Chris.
I'm sure I'm missing a few, and there are some from the recent past who are on this level as well. Who else do you like that's working today?