I had the same problem. I sanded them lightly and painted them with primer, followed by 3 coats of off white gloss paint. I lightly sanded between each coat too.
I also soaked the hardware in super power Dawn (the purple one for washing pots)and I discovered that they were brass underneath all the layers of gook. Now my cabinets look brand new! No one can believe it. It's amazing how it brightened up my kitchen too.
This is time consuming, but very cheap to do. I think I spent less than $20 on all of the supplies.