Difficult question to answer
I also just got myself a 3rd Dimension and I'm loving it, but the Hypergravity and the FB 2 have to be right at the top of my (ever growing...) list.
My guitar pedalboard currently has:
Polytune 2 mini tuner
BodyRez acoustic resonance enhancer
two Spark mini boosters
and I'm currently planning on adding a Brainwaves pitch shifter. I also own a second Spark booster and a MojoMojo overdrive, plus an HOF mini reverb and a WireTap riff recorder. (edit: oops, I forgot I also have a Polytune 2.)
I think, if I was forced to pick just one of these pedals as my favourite, I would have to say the SpectraComp. As a fully-programmable multiband digital compressor, the SpectraComp is marketed as a bass guitar compressor, but it really can be tailored to any instrument, and its capabilities are far beyond anything else on the market, provided you have the expertise to program it.
My second choice would probably be the Spark booster, the full size one for expanded controllability over the Spark mini, though in the two spots where I am using the Spark minis (pre-OD gain boost and post-OD volume boost), I don't actually require the additional controls, so that would be my third favorite.
Fourth and fifth spots go to the Arena (which I like slightly better than the Hall of Fame for the custom toneprints) and HOF mini. They allow me to program exactly the reverb I want.
My G System. Love it, despite owning just about every alternative.
If you want a stompbox answer, Ditto. Coolest pedal ever.