I loved the book V. It's been ages since I read it, but I remember it as quirky, which I tend to like.
Pynchon's writing is super-intellectual, very difficult to follow, and some of his jokes apparently require a phd in physics if you're to fully appreciate them. His first book, the Crying of Lot49, is by far the most accessible...Gravity's Rainbow is incredibly difficult.
In order of accessibility, I'd rank them: Vineland Crying of Lot 49 V Gravity's Rainbow (I own Mason and Dixon, but haven't gotten to it yet.) I loved them all, even Vineland, which was widely panned. It is definitely "pynchon-lite" though.
Don't read Mason&Dixon first. Read Lot 49. If you like what you see, you'll like the others as well. If you don't like what you see, you've got a screw loose, but that's another story ...
I read Mason and Dixon, but found Pynchon to be incredibly pretentious—in style, tone, and content. I don’t think I’ll be wasting my time again on his egocentric ramblings any time in the near future.