I've always been quite fond of Orly even though it is one of those more expensive brands. The bottle is big enough that it justifies the cost and lasts ages.
This top coat is quite thin, and dries very quickly. It doesn't smudge my colour polish underneath and gives a nice glossy finish. It also works great as a clear polish on it own, when I can't be bothered wearing fancy nail polish or spending an hour on a mani. It adds a bit of shine and vitality to my nails all in 5 minutes! And because it's all set within minutes, I can make a dash or start doing housework etc without worrying about it. It doesn't protect from chipping but then my nails chip within a few days for most polishes, so I wear UV gel nails if I want a long lasting mani.