Leviathan measures up pretty well against lots of rides that I've been on. I really don't declare a ride being in my top 10 with so few rides on it (wanna get on it in every row in different conditions first), but I do enjoy it more than all of the B&M hypers I've been on (Behemoth, Nitro, Apollo, Diamondback), Goliath at Magic Mountain and Millenium
I've always felt that the B&Ms in that list are all pretty tame force-wise in comparison to other rides, and the same goes for Leviathan...It's just that the extra little bit of extra height and speed made a big difference for me on this one. I've never been a huge fan of Millennium because of how massively spread out the layout is, so that was a given for me.
However, a ride like Leviathan never really stood a chance against a ride like Intimidator 305 in my opinion. I was lucky enough to get on that beast opening day, and the action and forces on it absolutely blew me away. I understand Leviathan is meant to deliver a completely different experience than that, but preferring more intense designs is just my taste in coasters. The same applies to Bizarro because that one's pretty action-packed as well. Leviathan pretty much totally delivers on what it was meant to deliver, though, and is a world class coaster.
I also feel like comparing Leviathan to Dragster or Kingda Ka is pretty silly. I really have no idea what elements you could compare at all!