GTX 960 is a fairly good miner, for NVidia-orientated coins especially lbry or lyra2rev2 based coins, or point it at Nicehash.
HD 4890 is too old, not much that's going to support it at ALL any more and the performance would be a sad joke for it's power usage.
Same on the GTX 550ti cards.
Nice hash would probably be the way to go, but unless your Electricity is fairly cheap i dont see you making much profit off them, you could always try your luck with some solo mining