It's quite expensive to be a purist in this day age. You can obtain comics digitally though and can be loads cheaper if you know where to go (legality aside, of course).
My opinion? All of the Green Lantern from Rebirth right up until Blackest night (which is last month) and all of Grant Morrisons run on Batman (particularly Batman R.I.P. Final Crisis and Batman and Robin) which is on going too.
I've also just read Powers by Brian Michael Bendis and it's quite simply the best thing he's done. The Boys by Garth Ennis is good, as is Crossed (which is a mini series in a sorta zombie apocalypse vein but with a twist). The Boys and Powers are on going but you can get a few volumes in trade paperback or trade hardback.
Oh and I've just finished DC: New Frontier which is awesome. You can get that in TPB. That was a really great limited run. Think Watchmen but set in the Golden Age DC universe (1950's-1960's). It's really great.
Marvel are completely not worth bothering with these days. After Civil War it's been pretty pants. Dark Reign was poor and Secret Invasion is probably one of the most boring things I've ever read for something that really should have been spectacular. I haven't bothered with Hulk and probably won't pick up anything related to it cause I really, really hate Geoff Leobs writing. I won't be checking out Siege or "The Heroic Age" by Marvel either cause the last few crossovers have been weak and they're even weaker when you put them alongside what DC have done in the past 5 years.
Marvel have a problem right now where their best writers (Ennis, Mark Miller, Bendis) all have creator owned series on Marvel offshoot indie imprints, and that's where they're putting all of their time and effort. And you can tell too, cause The Boys by Ennis is great, Powers by Bendis is literally one the best, if not THE best thing I've read in many years and Millers Kick-Ass was also quite decent.
DC are the opposite. They have couple of geniues in Geoff Johns (Green Lantern, the recent Flash: Rebirth mini series and the brand new Flash comic, the latest Blackest Night cross over and the current Brightest Day one) and Grant Morrison (all things Batman and Final Crisis).
This is coming from a former Marvel fan. I was an unsatisfied Marvel fan until about a month ago when I just started reading Batman and the Green Lantern. I'm a convert. I seriously think that Johns and Morrison are the best mainstream comic writers today, hands down.
So yeah, that's what's current right now. What I love. I've completely (and deliberately) missed out all the really good old Marvel and DC stuff but there is a wealth of that too.
