I have to vote Team Both. I make a couple of trips to local nurseries in the spring and early summer for new perennials and an occasional annual. I tried coleus from Al's in Woodburn this spring. Boy am I glad I decided to try them after years of killing them. With the help of the Coleus Forum they are alive and growing beautifully.
Most of the plants I collect (sedum, sempervivum and some alpine plants) I buy online, they are hard to find locally and not much of a selection. I also like to trade through the mail.
I did find a nursery about 2 hours away that has a wonderful selection of alpine plants. It made for an all day outing that was such a treat.