Well, put some more into the Indian defenses, because there aren't many tactical d4 openings. (1. d4 is known to be more positional, after all)
tactical opening against 1.d4?

This is a good question. Let me think on this and get back to you! Although, I have to warn you, I may seriously consider playing my answer because a lot of d4 players like myself are positional and it might just be a good idea to play tacticaly against them! :-)
You can try the semi-slav.
i been thinking about 1.d5, to challenge whites center immediately. so maybe the slav is worth looking into. thanks!

The Modern Benoni (1 d4 Nf6 2 c4 c5) produces an imbalanced position where tactical chances for Black are common. It has been good enough for a number of World Champions... Fischer (occasionally), Tal (a preffered weapon).

here are some SHARP openings for black against 1. d4:
- Benko Gambit
- Dutch Defense
- Gruenfeld
- Budapest Gambit

I like the Tarrasch defense, for the tension in the center, the numerous choices for Whtie, and the pin on the d1-h4 diagonal lead to many tactics for both sides, and evne though I have never had to play it in real life, I learned it anyways to be safe, tryed it against various chess-playing computers, and had pretty good success from some fun games that, even though had bad endgames for Black, had plenty of tactics weaved in.

Nf6 is my favorite response... leading to the King's Indian Defense, which is tactical, sharp, and exciting - but there is a but of theory behind it. The openings that Erik pointed out are nice - although i would place the King's Indian Defense ahead of the gruenfeld

When you say you're currently playing Nf6 against d4... which defense? Nf6 covers a lot of ground. I would second the notion of either the Modern Benoni or Grunfeld; they're both highly tactical lines that come out of Nf6.

Okay, I looked around a little, heh. I like Ray_Brooks suggesion of the Benoni, and Eriks suggestions are good too. But there are a lot of tactical defenses against d4 and you may be partial to any one of them ... it may take a lot of looking!
BTW ... playe4, what is the VonHennig Schara Gambit? sounds interesting :-)

Timpan -- Looking over your games on this site, it appears that you've only tried the Dutch once against d4, and when you did you used an offbeat line that didn't work out well. Why not give some of the other Dutch lines a try? If you steer clear of the Stonewall lines there are tactics galore and once you play f5 it's pretty hard for White to avoid the Dutch.

Whichever one Kramnik and Vishy played in all their championship games.
Well, the Semi-Slav was played often but it's only that sharp if White tries to bash Black. There are certainly many quiet lines like with b3 or cxd5. The Modern Benoni is probably the sharpest. Tal preferred it after all. However, this also means it's risky - especially at the GM level.
Whichever one Kramnik and Vishy played in all their championship games.
trouble is that whatever they use would be so heavily analyzed that you'll end up memorizing oodles of material rather than exploring something fairly off the beaten track. I've personally played with:
a. Albin CG
b. Stonewall Dutch
hi
i'm a tactical player. or at least i enjoy tactical games more than the positional ones. what opening should i try as black against 1.d4 if if i want a tactical game?
i'm playing Nf6 now, and i don't do that well with it.