Have you tried the gel (shellac) nails yet? I absolutely love them because they last so long (2-3) weeks and are hard as rocks the moment you leave the salon. They achieve this through a type of acrylic nail polish that hardens under UV lights. They are a bit pricey but so worth it if you want extended nail color.
PS. Never try to pick off the gel nail polish, I lost half my nail doing this! They need serious acetone to come free.
(Anne Hathaway, Natasha Bedingfield)