Breastfed all three of mine -- weaned the first at 11 months, reluctantly. My husband and I had made plans to go on a vacation and leave Peter (who absolutely refused to take a bottle) with Mark's parents. He went straight to one of those sipper-cups. Funny how your feelings change. Looking back I can't believe I did that just to go on a trip...
Anna didn't wean until over 2-1/2. Although I felt fine nursing her at that age, in retrospect I think I had gotten into a bad habit of nursing her on many occasions as a sort of human pacifier, while I was being too lazy to give her other attention, like playtime. She'd toddle over to me when I really wanted to watch the rest of a TV show or talk on the phone and rather than stop what I was doing, I'd just offer her the breast, knowing it would quiet her demands. The only bad part about frequently nursing a toddler this way can sometimes be that they get very demanding -- insisting on "nurnee, NURNEE" in situations where it would be difficult. By the way, she certainly had teeth and this wasn't any problem whatsoever.
By the time I got to my third and last child, I breastfed until my son was about 18 months and this was "just right" for both of us. The weaning was basically "child led", but unlike with Anna, when Thomas wanted attention I didn't assume he had to be nursed and spent more time playing with him, etc.
Anyway, I did want to say that there really is a wonderful & uniquely special closeness about nursing past young babyhood. Contact your local La Leche League for more information and support. They're a great resource.