Being fairly new to comics, I didn't know which comics were the current popular ones that people were reading, so as a way to find out--rather than just asking--I turned to the sales figures of the last quarter, and this is what I found the Top 10 were:
1) Wolverine
Wolverine #1 out-sold all of the other books in the quarter other than X-Men #1. I'm not sure if it's just that it's Wolverine, or because it's a #1, but I think I'll wait and see where the series goes.
2) X-Men
As I said above, X-Men #1 actually out-sold Wolverine #1, but the problem is that the sales dropped by half for #2. If it wasn't for this spike, the series wouldn't have even made the list, so again, not really a good judge of "popularity".
3) Brightest Day
Brightest Day had 6 issues during the quarter, all with fairly steady sales, placing it third on the list, though in reality, it should probably be at the top. I've never been a DC fan, but perhaps this would be a good series to change that.
4) Batman: Return of Bruce Wayne
Return of Bruce Wayne only had the one issue during the quarter, so again, it's not the best judge of popularity. However, being that it was #4, I imagine sales would have steadied off by then, so perhaps it is. It is only a mini-series though...
5) Avengers
With the Avengers film coming soon, it's hard to tell if this is actually a good title, or if people are just reading it out of hype.
6) Green Lantern
Green Lantern suffers the same problem as Avengers: Is it quality or film-hype?
7) Batman and Robin
Batman and Robin can't be film hype, so I might have to look into it. However, as much as I love Batman, but I've never really cared for the whole Robin thing.
8) New Avengers
I used to like the 2005 series, so I'd probably like this one too. Are these New Avengers the same as from back then though? I'm often confused by Avengers' line-ups.
9) Batman
A staple of the DC line-up, I'm sure I'd love Batman if I gave it a go. It's the only long-running series on the list, so I guess that has to carry some weight.
1. New Mutants (Volume 3) 2009 2. Astonishing X-Men 3. Uncanny X-Men 4. X-Force 5. Buffy The Vampire Slayer: Season 8 6. The Walking Dead 7. Wonder Woman
I read everything in the top 10, but not all of them are particularly good. Secret Avengers is currently the best out of those in the top 10. I also like the recent Batman stuff and the Green Lantern stuff is getting a bit more interesting, but they have their share of haters. I'd say avoid Avengers and New Avengers, unless you're really interested in those characters. If you're already familiar with the old JLI characters I'd say give Justice League: Generation Lost a go. The new Flash series, X-Factor and Captain America have been fun so far as well. Marvel's Chaos War is also decent so far.
I'm currently reading Zatanna, Power Girl, Brightest Day, Green Lantern, Batman: Return of Bruce Wayne. I might add Secret Avengers in that list, but idk not sure yet.
Popularity isn't exactly the best way to determine quality (Reality TV, anyone?). Try reading some reviews of current issues and learning more about writers, find out what kind of comics you're actually looking for (action, mystery, etc.). Seems kind of silly to start reading a series just because a lot of other people read it too.
Usually, I just judge the comics by the quality in the writing and the artwork and by what the reviewers said about the issues rather than by popularity because even though a lot of people read comics that are popular, sometimes they read it because a certain character (like Wolverine) is in it and they probably don't pay much attention to the story. It all depends on what you like in a comic and what characters are your favorites.