Has to be a V twin for me. Just for sheer rortiness when you twist the volume control. that said, the triple currently residing in the garage doesn't sound too shabby. Boxers just look too weird to my eye.
ive had a 300Ptwin, 600single, 600four, 955triple, and now a 1000Vtwin.
for a smaller engine the 300 went like a rocket, torquey and powerful with perfect balance. the GS800 feels the same, only 'more', i like it.
the simple air cooled single i used to call "the road drill", no top end but the torque was great, not much ever beat me at the traffic light GP. my mates ktm duke 640 is totally different, surprisingly little low down torque.
the 600four was a little lame but taught me how to use a gearbox properly to make the most of it.
the triumph triple was a surprise, creamy smooth yes, everyone said how great it was but i never saw the point, at the time an R1 had lots more torque and power and weighed and cost less, especially to service! the new tiger 800 has a totally different feel to it, i like the engine a lot just not the rest of the bike.
the big v-twin is just grunty, ticks all the boxes, torque, power, noise, cost, with well matched gear ratios its the best. ive ridden an 1150 boxer and found it a bit 'flat' feeling, if you pardon the pun.
all had good and not so good points, none of them had any bad points, but my favourites are the parallel twin and the v-twin. these days engine style wouldnt be a big buying point for me, its more the state of tune that would interest me. you can get fours with tons of low down torque (CB1300, bandit1250, versys 1000), singles with balance shafts and watercooling that are smooth like fours, parallel twins with 270deg cranks, you can get a 1600cc twin or a 1600cc in line six etc etc, pay your money and take your choice but dont just pick one engine configuration
I've had K's, oilheads, airheads, Moto Guzzis, Jap fours and lots of singles. I like the airhead boxers best of all. In line V's (Vincent, Harley, Ducati, KTM, Honda etc.) is the best configuration IMO, compact and plenty of character.
Transverse V Twin followed by the Boxer. Both allow the easiest access of all engines for top end maintenance and I prefer the power delivery over multis.
I have owned all types over the years currently have a Transalp and a K 100 brick I do love the v twins certainly miss the old Guzzi.s so tempted on another one MMmmmm we will see.
