Depends on the girl personally I like the littlest things best. I get excited from any surprise a guy has given me, from things a great as a love poem or a diamond ring to as small as a kiss or hug when I needed it most, special dinner cooked for me, or even a small craft. A boy once made me a rose in his art class that I keep to this day. To me it's the thought that counts and it means more to me when someone gives me something thoughtful rather than something expensive.
The one thing I've always wanted to get as a surprise has been a puppy...I've always wanted one to keep as my own without worry of having to get rid of it. However, that's just my one gift I always wanted.