Hm... I was shying away from it because one of you guys said it required a large investment of time to be worth it. Is this not true? If it can be played casually without massive frustration, maybe it is the one I'm looking for after all.
Haven and Hearth is just a bad idea, if you ask me. It's a lovely game, don't get me wrong (I'm alt-tabbed from it right now in fact), but it is
srs game for
srs people. That's not entirely true, but I don't think you're going to be able to enjoy it casually as there's a catch 22 of needing security to enjoy it (it's supposed to be a complete, kill-people steal-stuff sandbox) and needing to grind (at least from the perspective of a new player) for it. Playing it as a farming sim would work, if others would let you. I've never played it, but Wurm Online supposedly has some similar aspects and has less murdering and pillaging.
As for stuff I actually have experience with - Someone mentioned Wonderland Online, and that might work. If memory serves, it's a bit more like a traditional RPG (a really silly, Korean I think? one at that, riddled with Engrish and some stereotypical anime-ish stuff), but charming in its own way. There was also a somewhat robust crafting system and your own, private instanced space to make your own house and stuff. Probably one of the best suggestions I've seen, though far from perfect.
NosTale is another one (no idea if it's still around; I think it's coming around to two years since I've played). It's probably best described as sort of Diablo 2-esque only cutesy. I remember a lot of instanced areas with their own (self-contained) silly stories and such. I also remember it for its bitchin' rockin' music. As a matter of fact, I mostly remember it for that and the fact that archers were truly awesome. It's interspersed with typical MMO-ish kill things and take their stuff, but I don't think the grind was
too bad.
Note: Freeness stops here. It's probably too rich for the intended mileu, but I think they'd fit the ticket if you can afford it (and are worthy pick-ups in their own right). Also added some spoiler tags to not take up as much space.
Someone mentioned Neverwinter Nights - I think you can get the Platinum edition for $20, which is three full campaigns (of varying degrees of difficulty and plot-sensicalness - the original campaign is still laughed about amongst my core group of e-friends to this day). There's also enough community-made mods and servers out there that 'craptons' would not adequately describe how much there is. Haven't played NWN2 so I can't comment on that. Sure, it's DnD, but it's quite simplified and works as well as any other RPG.
The most expensive option I'm going to mention is Guild Wars. While a lot of people call it an MMO, that's not really the case (long story, not worth mentioning. Notably there's just a one-time fee, no monthly. There's four campaigns (Prophecies - the original), Factions (the black sheep that nobody loves), Nightfall (the one that revolutionized the game if you ask me), and Eye of the North (a tack-on that, unlike all the others, can't be played independently.)
Both ends will probably have to chip in $50 (Proph may be cheaper - I dunno), but you get a robust PvE environment that's probably best likened to Diablo with a story that's not just sort of there. Prophecies is your typical pseudo-Medieval European-ish setting (with dwarves!), Factions is Asian-inspired (and probably the hardest one of the three), and Nightfall is African inspired. Really, I could ramble about this for several pages, so on the off-chance it appeals to you, ask for more information and I'll give it.
There's also RuneScape (a terrible choice for srs gaming, but kinda-sorta-maybe-not-total-fail for your purposes). I think there's some crafting/building stuff, it's browser-based, and essentially a time-killer. I think the only stuff worth mentioning has a $5/month fee attached, though, so it's probably not even worth looking at. As the old adage goes, it might as well be called RunEscape, a-haw-haw-haw.