The nicest/easiest to fly - C208 Caravan. In terms of handling qualities Cessna engineers got her just right. Perfect balance of control forces/stability/maneuvrability. Would make an ideal primary trainer, but for the operating cost...
Not so easy to handle, but my all time favourite - Extra 300. To quote the late Duke Elegant, "cranky little slut on the ground and a hard ridin' whore in the air"
(o.k., He said that about a Pitts, but I think this description fits the Extra very well)
Pilatus PC-12 - a great blend of short field performance and decent cruise speed/range, makes perfectly smooth landings everytime due to huge low-preessure tires and shock absorbers. Perfect for short/unpaved runways. A bit heavy on ailerons, but that's the only caveat.
A320 - actually quite nice to hand fly (though feels a bit strange and "spongy" at times) and has a very comfortable cockpit. I have yet to fly a Boeing though...
Helicopters (if it counts) -
Hughes 300. very responsive, yet not too twichy. V eryeasy to control (for a helicopter), with virtually no innertia at all - it just follows your thought/hand. Not so nice for autorotations (sinks like a brick)
Bell-47 - opposite of the Hughes - sluggish, spongy, with huge control delays, very (I mean VERY) slow in crusie. Yet once you get used to it it's a real joy to fly, with unmached visibility thru the bubble canopy. Very benign in autorotations. More like a flying carpet than a helicopter...
