I like the quick play games that you can play for a short period of time and then stop. Great for when you are waiting for your car to get fixed or a doctor or dentist appointment or at the DMV. There are a ton of great classic arcade games that I would love to see ported. Even better if they updated them like Namco does. There are also alot of arcade updates that never made to the states that I would love to see released. Games like Crazy Climber 2000 and Hyper Crazy Climber and Elevator Action Returns.
I don't see how the two poll choices are mutually exclusive. Why can't an arcade game be 3D? The kind of games I'm most interested in for my iphone are games that can be played in short bursts but have enough depth and variety that you can sit and focus on them for longer periods if you have the time...2D or 3D doesn't make a difference to me as long as the game is good.
I've been more of a hardcore all my life, but recently awaiting future games i've been leaning more towards casual games like angry birds and cut the rope (lol). as a person said above me they're great for when you're waiting on a train, bus.. or on the toilet