None of the xboxs are any different in terms of how often they get RROD, and its been greatly reduced anyway. I would recommend getting the Elite as it is the best overall. The arcade is the same xbox, but doesn't come with a hard drive so that limits game saves after a while. So, i would recommend the elite.
I agree the elite offers more but it also has features I'm not that interested in like live and saving games on memory so I'm still taking the suggestion for Xbox 360 Arcade and adding the additional hard drive :-)
The Arcade and Elite are the exact same console. The only difference is the hard drive, which makes the elite a better deal. They both have live(which you must pay for seperately), and you can save games to memory cards. It would be cheaper to get the Elite.