I loved flying the Aerocommander on Coastwatch taskings. Great fun and very manoeuvrable.
I haven't flown a Bonanza but I did fly the Beech Sierra and that was very enjoyable too.
The Twin Otter was great fun but I must say, I really enjoy flying the Hawker 800XPi. Great combination of tried and true airframe, engines and systems with the very flash Collins Proline 21 and flight bag. It's my first jet so I haven't got much to compare it to but it handles nicely and it's performance on short field ops is pretty impressive.