Most Pterygoplichthys get big (which the 'common' and sailfins fall under).
As mentioned a Hypostmus Plecostomus is a common but doesn't get big(in most cases).
Note: There are 3 plecos being sold as common. Two are Pterygoplichtys.
http://www.planetcatfish.com/catelog/species.php?species_id=703
http://www.planetcatfish.com/catelog/species.php?species_id=88
As mentioned a Hypostmus Plecostomus is a common but doesn't get big(in most cases).
Note: There are 3 plecos being sold as common. Two are Pterygoplichtys.
http://www.planetcatfish.com/catelog/species.php?species_id=703
http://www.planetcatfish.com/catelog/species.php?species_id=88