I actually thought their last expansions were really well done (Darkness Rising especially). The biggest reason is it made PVE leveling so much easier. They added task masters outside of the forts/cities where you could get a quest for an instance (either solo or group) that you could go clear in 10-15 minutes for a really nice chunk of xp. We also later discovered some creative LOS issues in some of the highest level ones where you could park alts and a level 50 AE class on top of the entrance and have a shield tank pull the whole instance. 1-50 in 6 hours once we got it all figured out. They also overhauled the battlegrounds to the point where you could level almost exclusively in them if you wanted to. Champion weapons/Champion levels and quests were also nice, especially since classic was a no buff bot server. It's why I loved the classic server as it was basically DAOC up to date with TOA taken out. Even on an origin server with SI I don't think I could take the PVE leveling unless I had a set regular group.
If you want a class in high demand for groups in either RvR or pve I'd probably say this for each realm:
Hib: Druid, Bard, Hero
Mid: Healer, Shaman, Warrior (Skald for RvR, not so much group PVE)
Alb: Cleric, Paladin, Sorc (Minstrel for RvR, not so much group PVE)
Out of those the best for solo leveling would be hero, warrior, sorc, paladin. For RvR an 8 man group of each realm ran at least 1 of each class I listed as pretty much mandatory (and usually two of the primary healing class).