There are a ton of possible tankmates for the Blue Ram and all you need is a little background information on the fish to tell if they are suitable. The Blue Ram is from South America and any PEACEFUL cichlid from there will work. (Keep in mind that Oscars are from South America . Hence PEACEFUL) In my Ram tank I have:(Click the picture to view full size)
Angel fish, 
Cardinal tetras, 
Neon tetras, 
Cory cats, 
Ottocinclus,
Rummy nose tetras,
and Discus. Not to mention the many other kinds of Rams there are(Bolivian Rams pictured above). It all depends on :
1) If they can tolerate Acidic pH
2) If they are peaceful
3) If they will not tear up your plants
4) So just about any Tetra
