Many people will say you can do two pairs of rams in that size tank but I've kept them for many years and can tell you rams, especially German Blue Rams, get more aggressive with age. They also shouldn't be added until a tank is 4-6 months old. They are very sensitive to nitrates too.
You could do a couple schools of small peaceful fish such as Rummynose or Cardinal tetras, Purple or Regular Harlequin Rasboras, Threadfin Rainbowfish, Hatchfish, or any other small peaceful species. If you kept one pair of rams you could add 5-6 Cory Cats or 4 Dwarf Chain Loaches. Then a Dwarf or Honey Gourami for more color.