Back in the mid 90s when I played the Dragon, I really liked the old Leningrad mainline 7...Nc6 8.d5 Ne5 as black's set-up is almost identical to a YUG mainline. Though it seemed to work best in blitz, while in longer games white usually avoided the sharpest lines with 9.Qb3 or 9.Nfd2. I'm not even sure if it's still playable in our computer era, but I don't recall having seen an outright refutation either. 

The Modern Benoni also suggests itself, but the most Dragonlike and still reasonably sound may be Tiger's ...a6 system in the Modern Defence - besides after 2.e4 you might also be able to transpose into a dragon with an early ...c5.

I played the KID for some years when I was quite young, but somehow didn't have much success with it so I moved on.
The Leningrad has been an occasional weapon during the last years, scoring many points against weaker players, but the losses against IMs were disappointing. Perhaps it also had to do with the fact that I wasn't accustomed well enough with the positions. So perhaps the Leningrad remains a candidate, with he bonus that I have some experience with it.

I never really thought about playing the Slav, there are so many different variations, can you recommend a specific setup?

The Nimzo has 2 downsides: 
1. no fianchetto bishop 
2. what to do against 3.Nf3?
I watched the DVD from Jacob Aagaard about the QID but his recommendation against the main line seems good for white, while there is also 4.g3 Ba6 5.Qc2 c5 6.d5!?

The Blumenfeld sounds interesting, but as well as the Modern Benoni has one downside:
white doesn't have to enter it!
1.d4 Nf6 2.Nf3 e6 3.c4 c5 4.Nc3 or 4.g3 are likely to appear quite often!

That is also a problem with the Benko, which I tried to play in some games in the last 2 years: white doesn't comlpy!
I like the Benko quite well, but what after 1.d4 Nf6 2.Nf3 (seems to be the main white move below 2500)
c5 3.d5 ???
I tried some move order tricks like 3. ... g6 but there is 4.Nc3 and 4.c4 b5 5.cb5: a6 6.b6!
This Shirov variation seems quite good for white when black can't play 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cb5: a6 5.b6 e6!

So perhaps 3. ... b5 is best, but I have no material on 4.Bg5 and the positions are complicated and dangerous for black. In the only game I played that I got crushed horribly by a grandmaster! Does anybody have some experience here?
If I solved that problem the Benko seems an attractive choice, since the pawn structure is quite similar to the dragon and there is the dragon bishop! 

Am no great expert , but guess around 2300 standard myself. Anyhow here we go.

Something theoretically both sound and dynamic.

KID
Nimzo (plus Blumenfeld maybe)
Slav

Possibly even Leningrad Dutch, though takes longer to familiarise in my experience. Less solid against stronger geezers. 

All in all probably KID, using Gallagher book to kick off with. Khasim DVD may help and inspire. Most his books are naff, but Gufeld's KID book of his KID games worthy. 

If that doesnt appeal, Eddie dearing with Nimzo, Dangerous weapons thrown in. Blumenfeld - basically no material available.

if Slav, wait for James Vigus forthcoming book. In the interim, check out old Sadler book for ideas.

Bibs