I lived up north for a while, where I would wear boots about half the year to keep the tootsies dry and toasty.
However, now that I'm in the South, it's either sandals, athletic shoes, or dress shoes. When I was younger, I'd pretty much just sport a pair of new balances and be done w/ it. However, I often find myself in situations where that just looks silly (any place w/ slacks, basically). I'll usually go for the dress shoes, but there's gotta be something out there more middle of the road.
A fancier sandal is one option, though it's easy for that to cross over to something w/ a more feminine style.
Boat shoes are classic, though the leather ones can get warm.
A cheap pair of simple slip-ons are casual enough (they're slip-ons) while simple enough to pass anywhere. Plus, they have a bit of an 80's vans vibe.
Even a clean pair of chucks, shell toes, or indoor soccer shoes can get by in many settings.
The trend a couple years ago was to where shoes that looked like, to me anyway, fancy bowling shoes (mostly sold at department stores).
Please, don't even think about crocs.
I guess nike makes mostly "fashion" shoes now, but I don't see the value.
Anyway, what styles are you all sporting these days?