I'm currently in the second trimester, so a lot of the time, I can still wear some of my regular clothes, except a lot of the pants are starting to be phased out.
I saved my maternity clothes from last time around, but a lot of them are for a different season, so I can't wear them right now.
I had to get some new stuff, and managed to catch a couple of clearance sales at department stores, and got real lucky at a thrift store one day (which almost never happens--usually all the stuff they have is waaaay too small for me).
So currently, my faves are:
Maternity pants (khaki style)
Maternity pants (black)
A stretchy maternity skirt
A maternity cardigan that I saved from the previous pregnancy
XL sized non-maternity T-shirts (normal size is Med/Lg)