What games and what techniques do you favor for getting new players into the hobby? I have two approaches--much depends on the age and experience of the player. Basically, there's the adult players who have more than an average interest in military history and then there's the kids who naturally gravitate towards games on conflict.
For the latter, having those easy games with figures of some sort work best. Find out their likes regarding subject matter--be it tanks, planes, or aliens--and get them into a game on that subject. Tactical games seem to work best, but some of the strategic ones can work provided they have a very tactical flavor in combat resolution. We all know these games--the latest incarnation of BATTLE CRY! MEMOIR '44, TIDE OF IRON, AXIS AND ALLIES: D-DAY, etc.
For the adults, naturally I try to cater to their historical preferences and scales, but the best lure I've found is running a double-blind tactical game with two new players. My favorite system as of late had been ASLSK, but I think Mark Walker's LOCK 'N LOAD tactical system (BAND OF HEROES, DAY OF HEROES, FORGOTTEN HEROES, HEROES OF THE BLITZKRIEG, KELLY'S HEROES, ANY ONE BUT THESE HEROES--I'm joking on those latter two "titles") has more "glitz" and interaction. What I like about this is that you can provide the minimum of rules to get the players spun up and running and teach the rest as you go. Players then want to try another double-blind session or two but quickly get into regular face-to-face play. After just one win, they're irretrievably hooked.
I'll also admit to bringing in military types into operational-level games using PANZERGRUPPE GUDERIAN, although I'm thinking I'll use MMP/s A VICTORY DENIED from now on. One of the problems I often see in budding tacticians (whether uniformed or not) is that they can't focus as an attacker, especially when they think they have a lot of superiority. A couple run throughs as the Germans in PGG against thoughtful, competent Soviet play usually cures that and the lesson sticks in other games, other systems. The only problem with both games is that they can take a relatively long day to play to conclusion once people get the hang of it--and that can put some folks off.
Some other favorites for getting people interested in board wargaming:
Lost Battalion Games: SERGEANTS! (I used to use SNIPER! but no longer).
The ever addicting Steve Jackson game, OGRE (who can resist it?)
The AH version of the block game, NAPOLEON
Columbia's block game, ROMMEL IN THE DESERT
One caveat must be added. While they are fun games in their own right, I think it's unreasonable to expect that using STRATEGO, RISK (of any flavor) or BATTLESHIP will create wargame newbies alone and unaided.