I'm torn between two guys...

I've been interested in a certain guy for quite awhile. We have a lot in common and he seems to know me pretty well. A lot of my friends have even suggested we would be cute together. I've known him for what seems like forever and we're best friends, but I have trouble deciphering his emotions... One day he'll give me roses, and the next day he'll act like I don't exist and will go and spend the day with other girls. Sometimes he'll say he only likes me as a friend or "one of the guys" but he can also be very mysterious and suggestive... I've waited for him for a long time and I'm getting impatient; I don't know how to make any more moves. He also has told me that my mind is "very easy to mess with." Occasionally he'll tease me in certain ways, which make me uncomfortable.
Lately I've grown close to another friend of mine. I've known him longer and we've always been able to talk freely. He knows more about me than most people do, and we've been able to trust each other about some of our deepest problems. He recently asked me out and I politely refused - I honestly wasn't sure how I was feeling. We used to talk about everything we had in common; bands we liked, things we did, etc but lately all we talk about is how we feel, with the occasional dirty comment (which makes me slightly uncomfortable.) My friends aren't compatible with him and think we wouldn't be a good match. He also teases some of my friends, which makes them angry.
I'm looking for advice about which one would be better for me... Opinions please?