No kills, full stealth and as much tech as I can manage. 
 
Ton of fun and feels so much more challenging.  I generally break my no-kills rule for Maggie and Simons, as I like to lure them into mines, but beyond that it's all about the baton and using GEP to open doors I need to enter :) 
 
You?

I only just started my first playthrough ever a few days ago, and so far I've gone as stealthy as I can, but I can't say if I won't ever kill an enemy.
 
My baton has been great so far. Is a hit in the back with it lethal?

" I only just started my first playthrough ever a few days ago, and so far I've gone as stealthy as I can, but I can't say if I won't ever kill an enemy.  My baton has been great so far. Is a hit in the back with it lethal? "

I've always loved playing it as stealthy as possible and finding alternate ways to approach situations by exploring or talking to people. I mostly skulk around using the baton/tranquilizer darts in the early stages of the game while gradually upgrading the pistol. Rarely need anything else. Oh yeah, don't forget the glowing sword of doom!
 
This game is so fun to play.

I was going to write porn but then I saw Deus EX. Never played any but I will play Human Revolution if it's good. If I play it, stealth would be the way to go.

When I played, it was a lot of putting priority on finding security terminals as early as possible to shut down defenses.  But around that, I was generally always sneaking; I would still sometimes use the sniper rifle, but I was usually going around guards or using the electric prod.  But then later, I began working a horribly lethal cloak-silent footsteps-Dragon's Tooth strategy.  Sure it'll burn your supply of bio-cells like paper, but it's otherwise very efficient.
 
I was also a fan of the fully upgraded vison that let you see through walls at long range.  That otherwise relatively useless aug became awesome at that point.

I personally used multiple methods, Playing stealth, combat, lethally, non lethally, Something that can make people thinking that Deus Ex is half linear and half a sandbox game.
The game is a bit "experimental" IMO but it's stay fun to play :) .