I use xbmc and advanced launcher for roms. I have NES, SNES, N64, PS1, Dreamcast, PS2, Gamecube and Wii games. I had setup some of the older sega systems but I didn't play those games when I was younger so there's no nostalgia for me...and therefore, really no point in playing those games.
XBMC fetches the metadata and art work automatically and then if it makes mistakes I go to the mislabeled ones and search using the built in xbmc scrappers to fix them.
When I did use mediabrowser I used Red's gametime metadata manager, seemed to work okay but it was a bit more tedious as you had to go through the games one by one.
I just checked info on gamebrowser 2, looks like it will also grab metadata automatically from TGDB. I may have to look into this more since it seems to have a universal quit key which would be nice. But it'd be quit the pain to reorganize everything to go back to mediabrowser. Plus I don't think it looks as nice as xbmc. Decisions, decisions.