If I'm in the middle of a project and I find I need a bit I don't already have, (doesn't happen much anymore) I run down to the local big box and buy anything carbide tipped in a pinch. But given the time for advanced planning, I buy Whiteside bits online. There may be better bits out there than Whiteside, but I haven't found them and I ain't really looking. They just seem to last forever compared to the rest.
“We should be careful to get out of an experience only the wisdom that is in it and stop there lest we be like the cat that sits down on a hot stove lid. She will never sit down on a hot stove lid again and that is well but also she will never sit down on a cold one anymore.” - Mark Twain