This is going to sound fanboy-like, but so be it.
I really find that the Plimsoul is addictive. It's very, very musical, not just as a pedal to impress in a shop, but as something you want to use daily and don't grow tired of. It works in a lot of kinds of tracks, and you can do a whole lot of variations with it. The more I use it, the more I like it. The knobs are tweakable, and it sounds great in lots of settings.
Interestingly, I bought my son one (he's been recording 30 seconds to Mars' new album) but he's also a killer player, and he called me to say it's his favorite recording pedal, too. In fact, he uses it not only in front of an amp, but also at a low setting to warm up digital tracks, and it really works in that context. So there's that. The cool thing is that it can sound "soft" like a tube screamer type pedal, or "hard" like an OCD. It's very cool in that way, because some ODs don't mesh well with certain amps, and this one seems to go with most.
I also like the OCD and the Robin Trower ODs a lot, and the Fulldrive II is still a very cool pedal, but so far, I've had nothing that is as versatile as this Plimsoul.
The Mesa pedals are also very interesting and good sounding, at least to my ear. It's hard for me to find OD pedals I like as well as the basic amp OD sound, so that's saying something.
With the HX/DA, I tend to use overdrives more to shape the signal than to add gain per se.