with my ip4 i had two cases: an Apple bumper and a Speck Fitted.
the Apple bumper was great for everyday use. nice fit and finish, looked great on the iPhone, nice grip, basic protection, but still left much of the original design uncovered. i was able to pick it up very lightly used from a macrumors member for $10 or $15 - much better than the apple price!
i got the Speck Fitted free with the Apple case program and it was a great case for when i wanted more protection. i was very happy with it. it still felt great in the hand, very solid, no dirt got in, etc.
and from time to time i just used the phone without any case because it was a beautiful design.
now with my 5, i plan on finding a similar case setup, but i'm still torn on which ones.
no official bumper so i am looking at what is out there, but haven't found the ideal bumper yet.
i'm thinking i'll go with a Switcheasy Tone for my heavier duty case. i have been happy with Switcheasy products in the past (iPod touch case) and the Tone looks pretty solid.
Speck doesn't offer a Fitted for the 5, but they have the Fabshell (burton model looks ok) which is similar.
i did pick up a Griffin Reveal, but i don't think i'll keep it. it isn't as open as a bumper and it isn't as tough as more solid case like the Tone or Fabshell. so basically it doesn't really meet either of my needs.
also, i did order a Bodyguardz back skin this time around as well. i used one back with my iPod touch because the shiny back scratched so easily. i haven't completely decided if i'll put it on yet or not. i didn't use one with my ip4 and the glass never got scratched.