I don't think I've ever once been disappointed by Magicman, MDX or Spiff. Sure, Magicman has made me lose faith in him a few times for trivial matters (such as not liking Bioware games...heretic) but nothing majorly disappointing.
Spiff creates insanely great things, such as Iji and Dust Particles and doesn't put a single foot wrong.
And MDX shot way up there with Winterpie.