Hi Matt,
That depends on the size of your tank and what fish you already have. Bristlenose plecs do a great job on algae but are not really recommended if the tank is less than 25 gallons. Pit bull plecs are also good and stay small, they look similar to the otto. Take a look on http/www.planetcatfish.com/ and see if you can find any others.
How big is your tank ? What fish do you currently keep ?
Keep in mind that most plecs are fairly big "poop machines" so make sure you have enough space for one to grow out. Bristlenoses do a fair job of tackling some algae, but also keep in mind that these fish will not "clean" your tank - just chomp on some algae now and again. And there are lots of plecs that aren't algae eaters at all and wont touch the stuff - they prefer a meaty diet of bloodworms etc.
Also remember that most catfish are nocturnal, so you'll hardly ever see them
Steer well clear from Common plecs, sailfin plecs or Chinese Algae Eaters.