If you have forced lubrication, such as an oil pump, or a bath, oil is better. If not, use grease. Your front wheel bearing use grease.
The lubrication requirements of fire arms are not as severe as internal combustion engines. I like the semi fluid greases, I use a lot of Mobil 1 oil. I found greases hard to wipe out of the locking recesses of a M1911 slide, so I prefer oil or semi fluid grease.
But really, what is more important, is keeping the gun clean and well lubricated. Don't ignore it and expect it to run with dried, caked powder residue and dried, gummy lubricant.