I've had the best algae removal results with american/florida flagfish (jordanella floridae). Far and above any other "algae eater" fish.
SAEs, as mentioned, just get fat and mean, Loricariidae (at least the species that actually do eat algae) get too big. LFS mollies do ok, wild sailfins do better.
I had a 5g hex that I was using to see just how big a wad of brown hair algae I could actually grow. Pretty big, it turned out, about the size of a rugby ball, a glob at least 14" long and 10" across. It had consumed the entire root system of a big string of floating Brazillian pennywort, grown completely around a piece of driftwood that was wrapped in java moss, and was smothering several small swords. The sacrificial cycle guppies were nearly crowded out of all the remaining swimming space. As an experiment (and to further put off working on the tank), I dropped one (and only one) adult female flagfish into the tank. It immediately started slurping down strings of algae like a five year old eating spaghetti. It was a -lot- of hair algae, and it was amazingly all gone in three days. I wish I had taken before/after pics.
As luck would have it, I drained, moved, and severely trimmed my 33g altum tank a few weeks ago. The change upset the tank's balance a bit, and it experienced an outbreak of green hair algae around the oak leaves on the bottom. I added three female flagfish and shot pics and a time lapse movie. All traces of algae gone in two days:
Before...
After...
Time lapse movie-1min = 2hours (5mb quicktime)
In the past, I've watched them work over clumps of black/green slimy cyano, also black brush algae and duck weed. They are nice looking, tough as nails, indifferent to a variety of water conditions and temps, and, entertaining. Especially during their mating and territorial dominance "dances". Tail standing, backflips, barrel rolls, etc. They are generally peaceful in a community tank, although males will guard eggs with enthusiasm. My favorite algae eaters.
Rick