I've only tried drugstore brands, but I have two favorites depending on what look I'm going for:
Maybelline Full n Soft Waterproof -- natural looking lashes, but still gives some volume and color to my blonde lashes; not clumpy at all
Maybelline Lash Expansion -- for when I want longer lashes; not quite as clump-free as Full n Soft but still not near as clumpy as some others!
(I also always curl my lashes first, neither of these mascaras will curl your lashes themselves!)
Ones to avoid:
Almay One Coat Lengthening Waterproof Mascara -- this flaked off my lashes terribly; even worse than the non-waterproof version of this mascara!
L'Oreal Lash Out -- did a great job of lengthening my lashes but it actually straightened my lashes!
I also didn't like Maybelline Great Lash, but that's only because it took too long to dry, and my eyes are so deep-set that as soon as I blinked after I put on the mascara, I had mascara all over my face!