Joss Whedon's run on Astonishing X-men is collected in four trades or one massive collection. It's not only great for new readers but it's also well written, drawn and is full of references to older X-men story lines to appease the hardcore audience. Something for everyone. If you like drama matched with action then this a good series. Think Buffy but with superheroes.
Geoff John's current run on Green Lantern is great. It's all collected in trades and I suggest you pick up either the Secret Origins trade (if you don't know much about the character) and/or both of the Sinestro Corps trades which all the subsequent Green Lantern storylines develop from. Both good starting points. It's very much a space opera like Star Wars.
If you want pure undiluted Superheroics I would say try reading something like New Avengers (there are loads of trades out there) for Marvel or JLA from DC. New Avengers is both witty and fast paced action. In the last several years it's been the center of the Marvel universe. For JLA a good place to start is Grant Morrison's series written back in the 90's. It's dated quite well and has a cast of thousands. You'll be struggling to identify everyone if you're new to comics but that's fine, I've been reading them for over a decade now and I still struggle, I just go along with the exciting ride.
I think the best thing to do is just pick up a few issues off the shelves that you like the look of. Ask your local comic shop owner what he/she recommends, tell them what you like, to see what's best for you. Assuming they do their job right, they will only be recommending stuff they personally think is great, it's in their interest to have you back in the store buying more comics off them.
If you like an issue you can always get hold of back issues or the trades for previous story lines. After all every comic fan started somewhere. Fortunately there is soooo much variety to choose from, chances are you'll get to something you will like.