The best paint for bicycles is urethane automotive paint. This is going to be tougher and look better than anything out of a spray can. Urethane paint requires mixing 3 parts: color, catylist, and a reducer to thin the paint enough to spray. Urethane paint is also highly toxic and will hurt you if you breath it or get much on you. I knew a guy who professionally painted high end bikes with Dupont Imron urethane and even with the recommended respirator he had to stop because his health was suffering. I hope I talked you out of trying to use urethane. Auto-body shops can paint your frame. Auto paint is expensive and doesn't come in small quantities; you might be able to get a body shop to paint your bike inexpensively if you let them use a color they already have mixed for painting an auto or repair. When I wanted an inexpensive paint job I've used ordinary Krylon and Rustoleum spray paint. If you are careful you can get a decent paint job this way though it will lack the depth of auto paint and it will wear and chip easier than automotive urethane. Never tried them myself but some do it yourself bike painters swear by appliance paint for a good finish.. Others say engine auto engine paint is the best. In both cases your choice of colors is rather limited.
Sherwin-Williams as far as I know. I hope this helps(: