Don't forget the Darkstalker feat from Lords of Madness. Being able to sneak around things even if they have scent, blindsense or blindsight is nice. Still being able to sudden strike things with blindsight is crucial.

I'm currently playing a ninja in a campaign. The invisibility schtick can be amazing, sadly it doesn't last very long, at least at lower levels. You're looking at a single round of invisibility per encounter and if you're going to be facing more than that in a day you're going to start running into some real problems.

I ended up taking a level in swordsage, focusing on tiger claw and shadow hand, but a second so that I could have gotten wisdom to AC while in light armor would have been really nice.