Bike Tool Kit

I am looking to purchase a good tool kit for doing my own bike maintence. Ive been researching and havent fully decided. I dont want to purchase a set from bike nashbar because although it's cheap i doubt it will last me very long. I want to buy a set that will last me a lifetime. I have also looked at bikeshops to see if they sell tool sets but i have not found any that do. They seem to only have the good ones for themselves. Any advice? Any one else have a set that they've really enjoy. Thanks.