here is a quick list of cards that trash. (holy cow, there are more than i would have guessed coming into this...)
apprentice
bishop
chapel
develop
expand
forge
governor
jack of all trades
loan
lookout
masquerade
mine
moneylender
remake
remodel
salvager
spice merchant
steward
trade route
trader
trading post
transmute
upgrade
you can break those down into a few categories too if you are feeling crazy. straight trashing, trashing for money this turn, and trashing to improve that card. a few other cards may incorporate trashing in their play: embargo, farmland, feast, fool's gold, horn of plenty, mint, pirate ship, saboteur, swindler, thief, treasure map, and watchtower.