Any roleplay that I've truly had come to an end. A satisfactory end, not rushed to get to the next bit or restarted in the line of survival (both of which I've had happen on this guild site).
Only roleplays I've *ever* been in to fit this definition are from another medium of roleplay entirely.
Yhe first is a sci-fi roleplay in Starcraft 2's Cortex Roleplay, featuring a character called "Captin" (guy misspelled his character and it stuck), and a base commander (myself) who dual-managed the assets of an ice-world colony along with a quirky sniper character (also me). One way and another the base ended up losing the entire population of some 50 characters save these three guys against an alien civilization. A survival roleplay, basically, where the three characters were left in the cold to survive against the effects of burning ice and noxious alien fumes that could only be staved by the quirky sniper's very limited ECM rounds (Yes, we BS'ed our way through logic on that one). Eventually, the trio killed a boss, learned the secrets of the alien civilization and were rescued by a battleship. To provide a little background those roleplays were special collaborations of 3-6 random people (the more there were the more dropped), and characters would be built right on the spot using in-game assets with commands on the maps. Then we'd squish our characters into a general plot that grew on its own; a free jump in roleplay, in other words, though I've had sophisticated encounters there as well. I have unfinished lore business with the base commander from that particular roleplay, but I'm unsure of how to complete it here.
Same medium as above... and in fact the same map, though a different zone and set of roleplayers. My characters were the protector of a cell consisting of a Warlord; a being with power equal to that of a god, maintained by a crew of elder beings and a quirky staff that provided near constant comic relief when put by other roleplayers. We were a relatively open group, so that somewhat OP concept was OK, though in most cases I wouldn't have tried something like that. Eventually, the "wardens" so to speak ran out of power and were almost annihilated by Warlord (the survivors would echo in plotlines down the ages of my roleplaying there). Said warlord was destroyed by a human army... which just had the effect of releasing him from a physical prison. The result was the creation of a small group of roleplayers dedicated to exploring every inch of that particular plotline, an effort which has sadly become stale and one which I wouldn't mind to restart again. Why do I include this if it wasn't complete? It formed the foundations for the creation of many of my character concepts for years and helped solidify "what ifs" into reality via multiverse stuff that again I ended up BSing my logic through. It was a fun roleplay and worthy of mention. Three of the "warden" characters would go on to become dedicated characters through a number of other roleplays; one would be an oracle, another a teleporting warrior-mercenary and the third a pessimistic psionic who was the antagonist of many a roleplay until he met his bitter end to a roleplayer who specialized in humanoid poison frogs. That was a weird one, but I call it canon in my mind as long as it wasn't the result of bad roleplay... and it was a good ending. Kind of fitting too.
Another cortex one was based on a fantasy idea of two allied demon lords. I had used that concept a few times but was never able to complete it. It was eventually finished when the roleplayers of one particular game banded together and eradicated the demon cultists, soldiers and finally the demons themselves.
A little while after I used the concept again, and it resulted in the demon lords being defeated again... to a massive stink-bomb that eradicated the entire demonic castle and covered almost 25% of the map in irremovable green floating goo. That was a... weird ending. But hey, weird ends were the norm there, and they beat trolls/dissolving of the parties.
Another fantasy on the sophisticated side featured a 1000+ year old vampire with creaky bones wandering the world and passing his "wisdom" to a number of characters and finally falling to an RNG duel over a matter of pride between two characters. It was a good game, and I met a few good folks that day.
And another one, with a dragon king; 4 hour roleplay, I had a dragon king who walked with mortals and met a young wild dragon character and taught her the finer arts of not getting caught (with a number of close calls), with the assistance of an old knight serving the dragon. Long story short, the hunters used a spell to kill the dragon king, another dangerous and complicated spell was done to bring the king back, and the king came back as an angry demonic and powerful shade of his former self who killed the knight and heavily wounded the young dragon and proceeded to wreck the roleplay's town before being delayed by a dragon slayer who had been a bane all through the roleplay. Dragon slayer got knocked out just as the young dragon killed the dragon king. GG.
There's more tales, and many that have been memorable over the ages. Alas I don't think I've found such a sweet spot on RPG yet, though I've had a few good ones.