Honestly, I'm a huge fan of bemani games and I think Guitar Hero is better than Guitar Freaks. But that's only because IIDX is the best rhythm game, and the one I frequent. I think DDR has declined due to stepmania, in the groove and pump it up.
DJ Hero can never hope to be as awesome as IIDX It's the one case of Konami originals and JPOP > shitty mash ups They tried to get a piece of the pie with Rock Revolution you know how that went? http://www.joystiq.com/2009/08/10/rock-revolution-for-only-5-still-not-worth-it/
I've been playing DDR for years but only on hard and songs like Max 300/Unlimited/Legend//Paranoia Survivor, etc...game just became too easy and I would got bored quickly, at least these songs were energetic and kept you occupied. Japanese DDR Extreme was the ultimate version of the game(it had all the songs I've mentioned on disc). and nobody mentions "in the groove"? it was a pretty good DDR clone(ps2 era, from 2004 or so).
Segata Sanshiro mentioned ITG, but I was the same way. the slower songs would bore me, and I just did not feel engaged into the game. When my friend would pick it, I'd usually goof off while playing it. I'm assuming some of the developers felt this way too, and thats what lead to DDR devleoping the secret modes (hidden, wavey) etc. when you held select starting with 5th mix.
ITG is so popular because you can simply load your simfiles onto a USB memory stick and play them via the machine. Very popular with veteran DDR players, who find all the DDR songs too easy. My friend for example is 15 and can AA Max 300 on Heavy with ease, gets practise now from playing custom simfiles on an ITG cabinet in his local arcade. Stepmania is a much much cheaper solution to DDR and ITG mind, the kind of people who enjoy DDR tend to be those who'd prefer a cheaper solution.
