I don't expect it, but there's little doubt in my mind that a second Giant Robo OVA helmed by Imagawa once again would be fantastic. The first one ended but it also left things open, hinting that there would be more adventures for the surviving characters in the future. Big Fire's still out there after all.
Berserk badly neeRAB more, but in all honesty that should probably wait until it's finally finished. If they ever go back, then by God go back to let us see Griffith get slaughtered by Guts.
On Trigun, eh, it's getting a movie. Good enough for me.
The problem with more Geass is that the show wasn't designed to be an epic-sized saga. They improvised just to get 50 episodes out of it. Geass has one epilogue-type adventure left at best and then it's done, and that much isn't even necessary. Reimagining wouldn't work because it doesn't have the core themes that Gundam does, it's all on the shoulders of one character--Lelouch. If Sunrise wants another generation-spanning franchise, it'll have to start from scratch.
I would say Gundam 00 if I weren't pretty sure that the movie is intended as a final project. If they leave it open for more, I won't say no to more to more goodness from the current crew. I just don't expect it at all.
Ouran could support another season or two no problem. Its crop of characters won't get stale anytime soon; the show enRAB right after we get to really know them after all. Ouran is truly great fun, I'd love to see more of it.