The DT770s are known both for their comfort and for their closed-ness. However, you really won't know what you like, and *we* can't know what you like, until you've got some experience under your belt. A bunch of armchair philosophizing audio nerds can only tell you so much. What I would do to start with is this:
1. Pick up a pair of Koss KSC75s from Amazon, or your local RadioShack. They're incredibly cheap, sound simply amazing, and have been the introduction of many, *many* a headphone enthusiast into the high quality audio world. They should do a pretty good job of tiding you over until you've found something more expensive that fits your more complete needs, and on top of that they'll make an excellent uber-portable pair of headphones for say, working out at the gym, or other places you'd rather not take your nicer, $300-ish pair.
2. Find a way to audition some higher-end headphones before buying them, either at a head-fi meet (or just through contacting another head-fi user in your area), or going to a store that has a decent selection of *good* headphones to audition (sadly those are few and far between, but they do exist).
3. Don't expect to find the absolute perfect headphones for you on your first try. You might get lucky. Some do. For many of us, though, it can be a somewhat longer journey to the perfect pair in our price range.
4. Finally, if you absolutely *can't* be persuaded to wait until you've tried a few pairs, do yourself a favor and either:
A. Purchase from a store that has a liberal return policy (like Headphone.com)
B. Purchase used, through the forums here, so you can recoup most/all of your purchase price if you are unhappy with the headphones you get.
Oh, and welcome to Head-Fi. Sorry about your wallet.
