Your options are endless with a 125, here's 1 list I quite like.

10 sterba corys
10 peppered corys
3 BN plecos
10 khuli loaches

4 male Bolivian rams
2 German Blue males
1 Apisto Caca
1 Apisto agasizzi
1 Apisto Boreli
1 male or female krib (females often prettier than males)

15 congo tetras
6 Golden wonder panchax

Just an idea