What would be a good gun to look at for my next firearm?

I believe I got most of everything covered, but I am a firearm enthusiast. Currently this is all that I have: Mossberg 500A 12 Gauge Pump, Marlin Synthetic 22 Magnum Bolt Action, Mossberg 702 22LR Semi Auto, Chinese 16" Paratrooper SKS, Glock 19, Krag 1898 .30 Army Rifle. I am 22 years old, so as of now I can't spend a tremendous amount in one purchase. College is sure expensive. If you have some suggestions that will fill in the spaces of my collection I would appreciate your help. Thanks!