If you liked Gurren, Tiger and Bunny is probably right up your alley. It's probably the most fun anime I've watched in years. It's the same idea as GL, a comedy spin of a typically very serious genre, but T&B is a parody of super hero shows. It's got a very western feel to it as well, and really pulls off the dramatic moments when it wants to.
I'd also recommend Darker than Black, as many have said here. It's a bit too self serious for my tastes, but the animation is beautiful and the show ends up being quite entertaining. If you haven't checked out Cowboy Bebop yet, that's absolutely where you should go next. It's my favorite anime of all time. The way the characters are developed and how the action is choreographed to the music is amazing. With Bebop, the american dub is so good I'd whole heartedly say make sure to check it out.
If you're looking for mecha shows, there's always Evangelion. It's very esoteric and self serious, but a fascinating show overall. The remake movies are absolutely fantastic, too, but not sure how well they'd do for a non fan. There's also Eureka Seven, which is in a lot of ways a much more light hearted and fun Evangelion. It also has some of the most beautiful animation I've seen in mecha shows. If you can deal with a show being quite old, the original Mobile Suit Gundam has a lot going for it. There's a reason that franchise keeps going. It's some of the best mecha action in the industry. Just make sure to grab the japanese voice on that one as the english dub is just horrific. If you can get through that, Zeta, Char's Counterattack, Unicorn(UC), and Victory are all wonderful shows. Wing, 00, G, X and Age all have a lot going for them, but you have to be able to put up with a lot of cliched crap. The OVAs, especially the 08th MS team, all are extremely well done as well. Turn A is a divisive series. I find it wonderful, but it's a love it or hate it type thing.
If you're looking for a fun, Shonen action show, Hunter x Hunter is pretty amazing. You can jump on the new series right now as it airs. So much fun. Way better then the Naruto/Bleach stuff that clogs shonen shows now. It's written by the same guy who did Yu Yu Hakusho, another favorite and recommendation of mine, and he just kills it. It's just too bad he is so inconsistent in writing the manga. Really kills me to have to wait through his countless hiatuses, but damn if he doesn't come back to hit it out of the park every time.
It's not exactly what you asked for, but I have to through Kamen Rider Fourze and W in the mix as well. They're my favorite shows in a long time. They pretty much just are live action anime and I'd recommend them to anyone who even remotely likes anime.