Dark Age of Camelot is by far my favorite MMORPG. I started playing DAoC in 2001/2002 and played it continually for years. DAoC in my opinion was very stable and a well put together game. I don't remember there being many annoying bugs. Mythic did a great job at keeping up on everything to make the game enjoyable for the individuals that played.
I liked that there are three realms to choose from... with numerous classes to pick from as well. Because of the numerous classes/three realms it seemed to make it a bit challenging to keep classes balanced. But Mythic seemed to do a good job with that, even if it took a week to a month to catch. The leveling system was great. Back in 2001/2002 grouping was huge. That was just the way you individuals would level up. So it would give you the opportunity of meeting cool individuals that you could friend and group up with another day. There were many awesome individuals on DAoC. Some of which my family and I were able to meet in real life. Others we associated with on the game. Leveling up now days goes a lot quicker... If you have friends that have higher level characters they can just power level your character and you can reach the maximum level in no time. Even if you don't have a higher level friend you can just task/quest/grind your way to the maximum level in no time as well. The amount of time varies of course depending on the class that is being leveled up.
The PVP/RVR was awesome, the frontiers/battle grounds that were created made the game that much better. At higher levels you could go to a different realms frontier and take their keeps (the keep/towers later on). If you were in a guild you could claim the keep for your guild, which I thought was really cool.
I played on several different servers and was able to experience different classes and find which class I enjoyed the most. So like many other MMORPG's DAoC gave many great memories. All in all DAoC will remain my #1 favorite game because of it's creativity and how mythic helped shape/form how many MMORPG's are designed.