I can't say that I've ever owned a bike that I didn't like. I've had three. The first was a Katana. As RyanK stated, it's a great first bike. At least for me it was. It was a bulky sucker, but it got me where I was going. And to me it was plenty fast enough.
My second was the '06 FZ6. I enjoyed the heck out of that bike. Great performance, and it was a comfortable ride.
My third (current) is the Buell XB9SX. For me, this is a fantastically fun bike. It's more than fast enough for me, and extremely nimble. To me, it's just as comfortable as my FZ6 was.
The only bike that I didn't like to ride was my brother's Ninja 250. It felt puny and rather unstable. The first and only time I ever rode it was last year on Mother's Day, which just so happened to be the windiest day that I can remember. I was all over the interstate with this bike. By the time we got back to my brother's house, I was a nervous wreck.