Let's see....
Piston? No real favorite, but the Max Wedge looks pretty cool. Love my 216! (RR Merlin, but I'll never own one)

Turbine? P&W 123. Bullet-proof and dependable up to 140% rated torque pluss awhole bunch (gauge stops at 140)

Straight jet? PW JT8D. Developes power AFTER shedding a bearing through the turbines! (Seen it)
Both of the above have carried my butt through thick and thin.


Current fleet (subject to change w/o notice)
\'49 GMC 3/4-Ton , 60 Austin Healey Frog-eye Sprite (some assembly required), 2011 Dodge Avenger, 2015 Jeep Cherokee. No, they don't all run.
My other ride is a (B737)no, (B767)no, A320.... Update... was Embraer E190, now Boeing B787.

Knowledge is a wonderful thing, but ignorance means you don't know you can't do something.