Meh, you'd probably know this already, but I like:
-disruption (played a lot of Murkswarm, will be playing G next season)
-swarming (Bellawesome is a personal favorite, my Mamoswarm will be tested quite soon)
-T2 rush decks (Banette, Houndoom GE)
-low energy costs (IMMA CHARGING MAH LAZAH...meh, you take too long >_> )
-low number of basics in general
-surprise victories (Murkrow, Pluspower x3, Buck's, Sp. Dark, enjoy your 110 damage <_< )
-Wager (I don't know why, but there's still one in every deck of mine. Coolest card in format I guess)
-the Fire type in general. It's mostly low energy costs and high damage, and I like discarding. Heck, I even played Feraligatr back in the Neo days. xP
And I dislike:
-coin flips
-Claydol (I know it's a good card, I just refuse to play it <3)
-doing nothing during your first few turns (this is not Magic, you guys >_> )
-people having too much luck with certain things (especially topdecks, and people who rely on flips in their decks)
-mulligans (inevitable with this playing style =\)
-donking. I mean, especially Banette could donk a few times, but I always tried to use its second attack since I liked it more (also explains the near infinite discarding techs I've used with him over the past year) also I don't want the game to end on T2 -> this is not YuGiOh, either. That means I'm bored for another 40 minutes if it's in a tournament >_<.
...yeah, that basically sums it up. Infercatty and Nidoqueen d both don't fit in and I liked playing those as well, but that's probably because Nidoqueen could setup itself (making it quite fast for the d format) and Infercatty had Delcatty ex in it, which could hit for nearly 10,000 for 1 energy.