Dove make the best gradual tanner, in my opinion. It isn't strongly chemically scented, one bottle per season is more than enough, and it's inexpensive. I go very white (we're talking vampire white here) over winter and this always starts me back on my path to brown, even when the weather is terrible. It doesn't 'tan' you as such - you won't get that spray-tan effect...but if you're like me, you would rather build up a gentle tan a little at a time, and this product does that brilliantly. Added bonus? It's actually a decent lotion, even without the tanning component.
I've tried both the fair/medium, and the medium/dark - the darker one gets the result more quickly, so it really just depends what you're after :)
I buy this product regularly mainly as its fairly cheap and I can but a big bottle and it will last a while. Unfortunately it has that tell-tale fake tan smell... It does provide a golden glow, and is fairly streak free.