Yes, there are dozens of aspect ratios. 1.85:1 and 2.35:1 are the most common, but there are other tiny variations. For example, Fight Club is 2.4:1 for some reason. And Cinerama was actually 3:1.
Even 1.85:1 films are not technically perfect for widescreen TV. 16:9=1.77:1. I suspect the difference is so small, they just trim the edges.
The most troublesome aspect ratios are the ones between 1.33:1 and 1.77:1. For example Disney's Hercules DVD is in 1.66:1. It is NOT anamorphic, so on a widescreen TV, you are left with bars on all 4 sides. They could have produced an anamorphic version which would have left very narrow bars on the sides, but then regular TVs would have the 4 bar problem. Ideally, there should be 2 versions on the disc to choose from. My DVD is very old...perhaps they've fixed this on the newer versions.
BTW, I just saw part of an actual HD movie on TNT (The Negotiator). So now it's about a five to one ratio of stretched VS real HD based on what I've happened to tune in for.