The absolute best tan that I've found is the Loreal nutrisummer one. It comes in two different colours (light or dark so you can choose) and is one of the daily build up ones so you can have as many layers as you want, also makes it less likely to show any accidents!
I've never managed to streak it yet, and it is the most natural colour I've found (and I've tried them all, salon tans, st tropez, fake bake, dove, johnsons, loreal, piz buin, the list goes on!)
Everyone Ive recommended it to is converted! It also doesn't have that nasty fake tan smell that most of them have!