Shared experience with friends/like-minded is what I find the most enjoyable. Meeting one friend immediately comes to mind:
On Runnyeye server I had no idea what I was doing. It was my first MMO. I had no sense at all of what an MMO was, or what to expect. My first time in Oakmyst Forest another player asked if I wanted to group with them. Sure, sounds fun I thought. They soon asked if I was female, then asked if I was a virgin, then asked other things I won't repeat. I left their group (when I eventually figured out how). Perhaps MMOs aren't for me I thought.
A little while later I returned to kill frogs in Oakmyst Forest for frogs legs for a cooking quest in Castleview Hamlet. I cautiously introduced myself to a wood elf there who seemed to be doing a similar thing. We killed them together for a while, then went to the Peat Bog after having no luck. Then, luckless still, returned to Oakmyst. Eventually, thankfully, another player asked what we were doing (must have seen us there for quite some time, as we were). We told them. They kindly showed us where we could find schools of fish (literally right next to the frogs), and that you fish or gather for cooking ingredients. Of course we fished up some legs practically right away. We were very thankful and had a good laugh. Perhaps I'll give this MMO thing a bit more of a go after all. I wrote their name down in my diary.
I met a few other adventurers here and there in passing, but wanted to find my Frog-leg friend again, though had no real idea how to. All I remembered was they were a wood elf, so I started hanging out in the Willow Wood. I remember that I thought it was a busy place compared to Castleview Hamlet. I finally saw their name in the crowd there, a couple of days later. They were pleased I found them (or so they said!). They took me to the caves, and we had a lot of fun questing and exploring, though what I remember most is us running in terror from Slaverjaw. There was also a really scary ghost-gnoll on the higher level, we had a quest for him but he was impossible for us to kill. I didn't matter though, a lot of fun was had and we said we'd both make an effort to keep in touch.
Which we did. We basically spent the next couple of years adventuring together whenever we were online at the same time, neither of us having a much of a clue what we were doing (arguably I still don't), but always having fun doing it.