Stuff, Mainly Ryzom
Thus, I don't have to rewrite my explanations and opinions of stuff because of losing them to the bowels of the forum.

Origin: mmorpg.com/discussion2.cfm/thread/186994/page/1

My opinion is that "storyline" quests and roleplaying don't mix. Storyline quests usually only make sense if just one person ever does them. But the reality is that thousands of people save the same town over and over again. They get the same speeches, the same experiences, and the same gratitude. Storyline quests are for single-player games, not MMORPGs...at least, not MMORPGs that actually care about roleplay-conducive consistency and logic.

This opinion might not be understandable unless one places it on the foundation of a particular definition of roleplaying: in a massively multiplayer online environment, playing a role is not sufficient - instead, in-character interaction between players, the game world, and each other is the primary factor.

In replacement of "storyline" quests, I suggest live storyline events that have persistent effects on lore that evolves over the course of the game's existence. This isn't a new idea, it's been done in Horizons/Istaria and Ryzom, just to name two (there have been others no doubt, but I'm less familiar with them).
In Istaria, for example, two playable races and a racial capital city were unlocked in events.
The lore on Ryzom's website depicts the playable races' perspectives on what they think they know about their world, not necessarily the truth of the backstory. From there, that lore would've been updated to reflect the state of the races' knowledge as they uncovered fragments of their past, understanding of their present, and inklings of their future. Furthermore, the lore progress would differ between servers.

With live storyline events, your character has unique experiences that they can tell stories about to their metaphorical (or literal) grandchildren. Epicness is justified and genuine, requiring no exorbitant suspension of disbelief. Though not everyone gets to participate in every event, there are always more to look forward to (unless, as in the cases of Ryzom and Istaria, bad companies take over and neglect the game; note however that Istaria is now under the care of a fine company who are already getting their feet wet in running events, releasing more lore, and providing lore-grounded explanations for mechanics changes).

Ultimately, what I want, as a roleplayer and a sandbox enjoyer, is a storyline implementation that fits in the persistent massively-multiplayer environment instead of being an ill-conceived port from the single-player realm.

Origin: http://mmorpg.com/discussion2.cfm/thread/186724/page/3

- addendum (wasn't in the original but should've been): The community is high-quality, many of its members being more interested in helping newcomers than advancing themselves.

- addendum (blog edit for clarification and context): Any given player, even one who has mastered many skills, still has some skills that are low- or mid-level.  They can use a low skill in a group fighting low opponents without nerfing exp' , for example, or (see last point) they can use their higher skills on high opponents with a group of players ranging from newbies with only level 20 skills to three-month-old players with a couple of mid-level skills to masters working their low, mid, or high skills.

- No one ever mastered all of the skills, and due to the sheer time commitment it would require, likely no one ever will.

- An individual can't be entirely self-sufficient (unless they're dual-wielding accounts, and even then the upcoming point about crafting remains true):

=--- Healing spells absolutely do not work on self, leaving only the Self Heal action which has a long cooldown timer. Other defensive actions, such as Melee Protection Aura, have even longer cooldowns.

=--- The casting time/range/cost penalty on heavy armour, coupled with the time it takes to switch out a full set of gear, makes changing roles from melee to caster in the middle of combat impractical. Conversely, changing from caster to melee without switching from your light armour is going to make you a liability more than anything, unless the odds are in your favour and/or you know what you're doing.

If you have highly specialised magic amplifiers, changing between magic types isn't going to be optimally effective, but it works. With relatively generalist amps, casting different magic types is admittedly quite easy and effective.

=--- It used to be said that you can't really solo in Ryzom. You can, with most skills (healing is exclusively group-oriented; the debuff skills must be coupled with similar-level offensive skills, halving the progression rate). But, as the very existence of that rumour/myth demonstrates, it's more difficult than grouping, and at some level ranges for some skills, much moreso.

- Mastering enough crafting and harvesting trees to equip oneself fully with whatever armour or weapons one wants is extremely time-consuming, so most people go to other people for their crafting needs.

- Most of the groups I experienced did set up roles, mainly according to what skills the group members wanted to train at the given time, but at least a healer and a tank and/or damage dealer were always needed. The guilds I have been in mingled level 20s with level 200s, and not only as healers - as long as the higher tanks were doing their jobs, the lowbies could do anything they wanted. At times I saw amazing exercises in player skill, efficiency, and effectiveness.