Join Date: Mar 2008
Location: Manchester, UK.
Grey Knights are good army - they play very similar to Eldar lists, but without some of their funky rules.
The typical solid Grey Knight list is based around 2 Land Raiders, 2 Tactical Grey Knight Squads, a Terminator Hero, and a Bodyguard. That's 1000 Pts, and good at taking on quite a bit.
They are unfortunately expensive models, and in game, so it'll hurt if one dies, but there's no denying their effectiveness.
However, due to their model size, being Fearless, and general weakness (you're paying nearly double for a person that's not tougher than a Marine).
To win, Tyranid's do well, Eldar, and Orks are your best bet.
It's not a black and white question really, there are different shades of anal probing,
a rectum spectrum, if you will