I wear the Asics Gel series. Each pair generally lasts me a year. I have a high arch and they work well for that. I think I'm about due for a new pair, though... I try to snag them whenever a sale pops up so they aren't terribly expensive.
DO NOT wear fashion shoes just because they look nice/cool. If you have flat feet, go ahead and wear your Converse or your Toms because they feel good. Furthermore, try to break in your shoes before wearing them to work. I have a place where I walk (really nice wilderness area) and that's where I go to break in work shoes.
I'm sure most everyone here already knows as much, but you can't say it too many times... can you? ;D