god.... so many memories....Let's see if I can pick a few without writing a wall of text so large that it becomes illegible...
My top five most memorable, in semi-chronological order
First time I saw/fought Steelfleece Baldarich is one I'll never forget. I was dicking around on an alt/mule shortly after I started, as a little taru whm with no sub, like, level 11. Tak was only like... 20. Anyway, it was 2amish, and this @#%^er was mowing down other nublets left and right, to the point that I think every single person in the zone at the time, all of us under level 30, were there trying to help each other survive, because it was a long ass hike back from bastok. Then a group of higher levels shows up to fight him. They're all 50ish... so they didn't fair a whole lot better than we did, but then the 20-30 nublets got all rallied around them and we spam cure I/II'd those crazy bastards for a good half hour while they chipped away and steelfleece.
Oh, and I've got one about Exo and Gustav Tunnel, too, though it's not nearly as epic. He was skilling up his greatsword (I think?) with Enshiro (badass mutha@#%^a and someone who made dual boxing an artform before people knew it was even possible; whom I had known since the first week I started playing) while they beat on skeles in the back of gustav's first crab room. I don't remember exactly what brought me down there, but I ended up joining their little escapades and being introduced to exo (whom I'd seen on alla, but never met in game). Poor bastard had no idea how stuck with me he'd get.

(I think that was when I got my NB pearl, vlor, but it may have been a bit after that. I don't remember exactly because jesus@#%^ was that a while ago)
I'm also part of the crowd who took part in Siren's first besieged, and I was one of the major instigators who got the pre-besieged shoutfests to their incredibly corny levels of consistent ROARiness, though I'm not arrogant enough to think I did it by myself. I also happened to be really good friends with Doomcky (another guy I knew since I started), who at some point on earned the title of "Siren's Sixth Serpent General" from the players who did besieged frequently, because he was at every single one that was in reasonable US play time, and worked to heard the cats that were the players to help people figure out what to do and what not to do. Being in his alliance during besieged was always a hoot. (For the record, some people tried to call me the 7th serpent general, but I wasn't able to be on as often as doom was, so it didn't really stick. Still <3 those guys, though, whoever the hell they were) Hell though, Doom had quit by the time, but he reactivated his account just for our 3000th consecutive win, and those of us who remembered him had a field day with that.
One of my proudest moments as a mnk and a member of my long-time LS came the first time I fought Bloodlapper. We were in a lowman group of Blm (Dekka<3) Blm (Baratheon<3) Rdm (Springheeledjim as Auroralee<3, unless bara was DBing and I forgot) Thf (Severed<3) Mnk (Me, who came on mnk because it was what was geared and I happened to have a pop I didn't need, also, this was before my pup was actually good, or even 75) I wasn't really much use for the fight itself, until- wait, let me get to that). We had 4 pops and needed 3 pairs of gloves, we got the first two down without much issue, but just as we start working on the third (this one was for the thf, who had blm but came on thf for TH), one of the blms d/c's. Then the rdm d/c's. and the thf and I knew that if the rdm d/c'd, the other blm would too, because those two lived together (or the blm was DBing, I can never remember), so we were kind of sh*tting ourselves because he REALLY wanted those gloves. When the other blm dropped, the thf manages to get hate, slapped on all his eva gear, and I realize, "Oh sh*t, we can still do this! DUDE, KITE THAT @#%^ER!" "Wha-? Are you gonna..." "JUST RUN! @#%^ING CHI BLAST, YO" "@#%^ YES, HERO!" so while the other three proceed to have connection issues, scrambling to get back on, the thf kites Bloodlapper all the way around the crater in meriph where he pops while I'm F5 boosting like my life depends on it, and he manages to pace himself so that he comes around just as I hit 10-11 boosts almost every time. I don't have sh*t for chiblast gear, and we grind that @#%^er down from ~80% to about 30% before the blm/rdm duo finally manages to stabilize themselves, just in time for the thf to eat goblin aggro and bloodlapper to gore my face out.
Finally, my first Tinnin fight, which I
think exo was there for, but I may be wrong. I brought pup, and was pumped because I was finally skilled up and geared out to do some pup nuking. It goes fairly straightforward until sh*t hits the fan and we have a full alliance wipe. Now, obviously tinnin pops were not exactly pleasant to get at the time, so the crazy @#%^er who popped it (Darkscyther, you loveable crazy @#%^er) dropped from alliance, not as a rage quit, but so he could @#%^ing bio-aggro-die-rereaise spam tinnin to keep him from despawning. I realize that, hey, I'm a @#%^ing pup, even double weakened, my nukes are still full power, so I drop from alliance too, and proceed to time my nukes up with DS's bio's, and I abuse the sh*t out of pup's amazing hate-free nukes. Between Bio II's dot and my nuking, we shaved a good 40% off of Tinnin's HP while the rest of the alliance recovered. That was the day I decided pup would be my main, regardless of what people thought of it, and I also managed to convince a few of the people there of how badass it was (the rest either already knew, or were from my LS, and didn't care because it was
ME on pup, so it was funnier to just pretend it never happened, or act like I was stealing credit from my puppet.)
God dammit, I think this thread might get me to resubscribe too...