I *highly* recommend everyone try shaving oil; and for free, now's the time!
I shave my head every other day, and I've tried everything. Creams, gels, electrics (foil and rotary), old-fashioned straight razors, etc. I get the closest, least irritating shaves with oil and a Schick DiamondFX blade (works better than the Mach3 for me). I use "King of Shaves" brand oil, and considering you only use a few drops per shave, it's not too expensive. What's nice is that the wetter your face, the better your shave.
And I have oily skin, doesn't matter (in fact, it may help!)