I don't really like I-4s, too buzzy, but damn, do they work well and pull hard.
V-twins can be hit and miss, some are agricultural, some are torque monsters, but they are nice and narrow.
V-four, like a torquey twin, on steroids, VTEC for the win
Singles, well, yeah, off-roading and keeping it light and simple, it's the way to go.
Twins, haven't ridden many, last one was a 2-stroke, so I'm outdated.
Boxer twin, great engine, character, decent power, balanced, liked how it felt
Flat-6, if you want a power cruiser/tourer, it doesn't get any better, basically a Porsche 911 engine feel on a bike.
Triples, flat-four, don't think I've ever tried