I've done a ton of wheelies on my CRF50, but never any on purpose on a full size bike. I can wheelie a CRF50 all day long though. I never transferred that to big bikes.
I've done a few accidentals on big bikes, twice in absolute spectacular fashion. First was back in the late 90's sometime. I had a CRF600F3 that I commuted to work on. We had a long straight in road to work. Speed limit was 25, but people sped triple digits sometimes. Private road, dead arrow straight, for a long ways, you get the idea. Company finally installed 15MPH speedbumps. They were pretty far apart. One day I'm coming in to work, and I am behind co-worker in his Honda CRX Si. I decided to show off by blasting past him on the bike (we always raced when we were in our cars). I got over into other lane a tad too early, so I gassed it just as I was hitting the speed bump, which sent me into a wheelie. I was full throttle and bike kept coming up and up and up. Never having done a wheelie before, I had zero reaction to this situation, so I kept doing the wheelie and I kept accelerating and slowing going up more and more. I was in a pretty tall wheelie when I finally got alongside him (he floored it too trying to race) and flew past him still in the wheelie. Luckily the next speed bump knocked me back down onto two wheels. Later inside work, he thought I was a badass. I never told him that was totally by accident haha.
2nd time was 8 or 9 years ago on my 2007 CBR1000RR. Came to a stoplight, and next to me a Mustang pulls up. 2 lanes in same direction, but on other side of intersection it starts to merge into one lane. Anyways, as we're sitting there, Mustang starts inching forward, revving engine, etc. Light turns green and he gets me on the jump, I give it full tilt throttle and pass him in a wheelie. At this point, I've done plenty of accidentals, so wheelies weren't scary anymore. I looked over at him, in a wheelie, and the look on his face as I passed him in a wheelie was priceless. He was full throttle and I still easily passed, in a massive wheelie haha. I ruined his day as I'm sure it looked like I was mocking him.