Key decision you need to make is if you want a 2 or a 4 stroke engine.
We have a tiny 2.5 HP Suzuki 4-stroke. I'm not overly impressed with it. It's unreliable because the itsy bitsy jets in the carb keep clogging and take a lot of time to clean. The magneto died once too. It's fairly serviceable, but there are some annoying parts, like lining up the coolant pipe in the leg or the gearbox oil change. I'd say it's an okay outboard at best. Major advantage is its weight - I can give it to the first mate to hold, then clamber out of the dinghy and take it from her to put on the pushpit bracket.
Neighbour has an air-cooled Honda, and while noisy, it seems a better design. Might just be me though.