Asuran Scan (Asura) -- Asuir (Dahnel) told me about this skill the other day, and I give him full credit for my liking it! Why do I like it so much? IT WORKS WITH SPIRITS! That's right! Lay down a few choice spirits, throw Painful Bond on some enemies as well as Asuran Scan, and watch the damage go! It's great! Thanks, Asuir!
Great Dwarf Weapon (Dwarf) -- This is a really cool weapon spell that I like to throw on supporting melee characters as I'm healing. When I'm Channeling for offense, I'll instead still bring Splinter Weapon as I enjoy slapping that on the main tank and letting the damage fly. But Great Dwarf Weapon is great for Ritualists, because our class can specifically utilize the Weapon Spell aspect of it to bounce other spells off of it. Wielder's Boon works off of it (great for those supporting melees!) and should you happen to be channeling, Wielder's Strike works as well. I also like it because it lasts for a full 20 seconds regardless of faction rank, so you know you'll have time to do stuff. I can normally maintain it on 2-3 allies, which ends up being a LOT of damage and a LOT of potential knockdowns.
Great Dwarf Armor (Dwarf) -- Yay! Prot skill for the main tank that we can actually put on! The recharge is a little long for my liking, but it's nice if it's only one ally that needs it, such as in a controlled dungeon.
Summon Mursaat / Summon Ice Imp (Asura) -- Ah, the summon spells. Cool stuff for a Ritualist, as Boon of Creation will actually give you the bonus for this (although I haven't quite tested if the Spawning Power bonus applies to them...anyone?) really neat summon. I added both of these because I use them equally in different situations. If it's just a free-for-all party, I like the Mursaat because of the Weakness it puts on folks. If it's a tightly-controlled party setting with a main tank, however, I love the Ice Imp, because the AoE slow is a real boon in all the dicey dungeons that GW:EN has to offer.
Air of Superiority (Asura) -- What a cool spell. I don't like that it's not cast-over like Ritual Lord is (but rather requires you stand still and don't do anything), but everything else about this is wonderful. The bonuses are awesome, from added Energy and Health to completely resetting your skill timers! It's awesome for a spirit spammer, and I've actually tried a Defensive Spirit Spammer using this skill, and it worked rather well!
"Finish Him!" (Norn) -- There should always be someone in your party with this skill. It's just too useful for boss fights and the like.
Light of Deldrimor (Dwarf) -- This too.

---
So yeah! I guess those are all my favorites at this point. I'm interested to see what the rest of you guys are coming up with! How's GW:EN treating all of you?!