I've seen a lot of different fighting rings. The square cage (which won't be on the poll lol) all the different cage- gons, the circular cage, the modified boxing ring, and different variations of the ring.
Personally my favorite is the round cage. I like it a lot because it has no corners and looks cool
Also I like the hecto and octo rings. I think it's as close as practically possible to a true MMA fighting surface. It doesn't favor strikers because there aren't deep corners and doesn't favor wrestlers like all the cages.
edit- also for those of you that have seen the Pele Chuck fight I really liked the bottom rope catcher so they couldn't slide out. The only thing I would change is that no strikes could be thrown from outside the ropes like when Chuck pinned his head and nailed him for 6 minutes straight.
I think the least practical but most true to the sport would be a big ass piece of circular canvas that would be really big, like 60 by 60 and have no walls or anything to put anyone against and that would be better. there would be a warning area that you couldn't pass or would be recentered.
What does everyone think? What's your favorite ring/cage? Do you prefer what is exciting or what is closer to the heart of MMA?