I'm humbled by the previous responses
but here's my smaller-fry faves among twenty or so types:
Taildragger: Steen Skybolt
Mine was a 180hp built by my old Doctor and his lovely wife. I'm not sure I ever became a master of taildraggers but that little beauty taught me a lot about how to use my feet.
Small nosedragger: Glasair III
Pretty little thing. Fast & relatively easy to fly though landings could be thought provoking. Currently fly a II though with a bigger engine.
Light twin: Piper Geronimo
Souped up Apache. Fun and just deceiving enough to kill ya...flew in and out of a 30' wide and 2000' long strip in NorCal which refined skills somewhat. Thankfully.