I've liked all that I have put in but I haven't had many. Otos and bristlenoses now. My first pleco was a spectacular starlight pleco. Then I found twig catfish at PS. Both are good sized fish and would look better in 4' tanks than 2-3' tanks.
I would say albino bristlenoses. They stay smallish (4") or so, and are good little algae eaters. They will rasp the older leaves of Echinodorus (sword plants), especially if they have some tasty algae on them. As a previous poster mentioned, they keep the glass very clean, so I put up with having to trim off the odd sword plant leaf. They do not become aggressive as they age, either, or go after fish to feed on their slime coat.
They are also very long lived. I have one in my 66 gallon tank that is at least 14 years old.
Snowball pleco. I forget the L# though. I think there is a few, like a small, medium and a large size. I have the small one. He's about 3 inches at best. Hides a lot unless it's very dimly lit. From what I recall of my research, they don't eat algae. That gave me a lot of confidence that he wouldn't eat my swords like my albino BN pleco did (no matter what I tried to supplement for him to eat). My snowball pleco is my avatar. One of my favorite fish in my tank.
One should remember that those orange and brown striped, mini pleco's primary food source is rasping away at slowly rotting driftwood, and that they can loosen driftwood attached plants/mosses with their activities. They're great fish though, they have more personality, for their size, than any other Loricarid I can think of.