In addition to doing a lot of PvP on my various characters, I've also picked up Rift recently and have been playing that pretty extensively. As you can imagine, as an altoholic, having 4 new "callings", two new factions and lots of new zones to quest through, on top of new dungeons, new warfronts and lots of other things to explore has me pretty engaged at this point.
So far, I've managed to level a Guardian Mage to 26 (running as a Necromancer/Warlock/Chloromancer combo) and also managed to get a Defiant Cleric to 25 (running as Justicar / Shaman / Druid).
There are a number of things that Rift seems to be doing really well at this point. First, every calling has at least one soul that includes a pet, which makes leveling certainly faster and easier. On top of this, 3 of the 4 callings have souls that include healing abilities. I'll caveat this by saying that I haven't played a warrior much at this point, so I'm not as familiar with the abilities of this calling. If there's a warrior soul out there with significant self healing, I'd really appreciate the info.
The interface and the questing system seems pretty intuitive and the zones are really well laid out so far. One of the things that I definitely miss from the redesigned WoW is all the flight paths. Basically, in Rift there is one major town in each zone that includes a portcullis that will teleport you to the major town in another zone that you've visited. Some of the zones are quite big and this can make travel a bit of a hassle. On the positive, you can get a mount very early on which helps a lot.
The various Rifts and zone events also help break up some of the routine of questing, providing fun things to do in a group, and decent rewards. The only downside to some of these events is if you're on a server where groups don't tend to rally to defeat the events, you can find the NPC's that you need for quests wiped out by invasions for a decent period of time. It can be a hassle if you're just trying to quest and do your thing.
On the WoW front, I've also rediscovered the joy of PvP on my shadow priest, so he's been getting a little extra love these days. I've been trying to do more on my Shaman, but just having a lot of trouble finding a PvP spec that I enjoy. He might be destined to be the one character under 1,000 honorable kills.