The "best" hosting for ASP.NET will probably depend on your budget. Both WinHost and DiscountASP.NET are good, except that the latter charges extra if you want a SQL Server database. On the other hand, they built their own control panel and have a bunch of IIS and SQL Server tools that you don't get with other hosts.
If you want to go high-end, check out OrcsWeb. Another good host is AspWebHosting.com. Their site looks tacky, but they know their stuff, and I've had a really good experience with them. (The only one that I haven't used is OrcsWeb, but I'm keeping them in mind for a future project.)
Good luck.