Like a lot of you, I've tried out all the front-ends over the years and at some point ran across Mike Billings' "CocktailFE" program. It used the MAME control keys, was configurable somewhat as to what graphics you could put where, and was clean and fast. Since it used Windows fonts, it had the bonus feature of working with the ClearType feature of Windows XP. This made it look beautiful on my setup. There has been another fork of Mike's project called "EmuWizard" which added the ability to use other emulators (somewhat) but didn't add any new display features other than using other graphic formats. This wasn't very useful as all MAME art is in PNG format anyway.
Then one day I took the family to Pizza Hut, only to find a new arcade machine called "Ultracade". Ultracade looked to me like a MAME ripoff with a nice frontend, but after later research it turns out it's legitimate, or at least it hasn't proven to be illegimate. Has anyone tried to look at the hard drive of an Ultracade PC to see what's there? Anyway, it had a beautiful interface where you chose the games by the marquee on the left (2x4 grid) and it shows the live attract mode running on the right. Newer versions of this machine don't look as good to me as it now has some crazy looking broad on the screen with the marquees in a rotating semicircle on the right and the live attract on the left.