Captains are compared a lot but to be honest I think after the captains, skipping over the XO or security men etc. the engine room head honcho is probably actually the most influential character after the captain, in each series. Just my personal opinion. I haven't seen this poll before. I always would have thought Scotty, but I have got kinda endeared to Trip and his impulsive redneckery. The guy looks and acts like someone who you would expect to see half under a car with tools scattered around. Ultimately probably still Scotty... though O'Brien gives him a good run for his money.
personally i'm a Tucker fan... Scotty and Laforge were cool, can't argue with them for engineers, but i liked the way Trip did things and got everything done M
I want to say Scotty, but I keep remembering his insistence that it takes 30 minutes to restart the warp drive in "The Naked Now" ("I can't change the laws of physics.... I've got to have 30 minutes!") vs. Trip doing the same thing in "Divergence" in 2 minutes ("That's impossible!", "Watch me!")
Scotty. Definitely Scotty. "Mr. Scott, how long to refrapulate the agromanilators?" "Two weeks, sir. But since we don't have two weeks I'll have her ready in half an hour."
O'Brien, taking into account all the handicaps he has to deal with: slapping together Cardassian with Federation technology, the enormousness of the station, and no true rest since he has to go home to that whiny needling wife.
That whole time-inflation nonsense was a joke by Scott in ST3, and sadly picked up as factual by people after.
Scotty is the main man. I'd say O'Brien but for some reason he can't decide on the rank he holds in Starfleet. From transporter chief on the Enterprise to Chief Petty Officer on DS9. Was O'Brien ever an engineer or was he the default mechanic for cast sake?