I miss playing my Grid Armor MK 3 Engineer and how stupid OP it was at the time. I literally almost cried of happiness when it dropped as it was the most sought after item in the game. Could've easily have sold it for hundreds of millions (which at the time was very rare to have such amount). I decided not to sell it and use it just because of the arena in one of the major cities (cannot remember the name) and wanted to slaughter everyone due to it OP'ness
I also miss my lvl 175 Sniper on my lvl 50(?) Agent before they nerfed the twinking due to Mochams, etc. Agent later had that cool trenchcoat thingy from that one raid boss (Terasque or something;pre any expansion). I remember grinding so hard for that floating badge thingy where you had to kill the huge robot and etc for. Was part of a large progression quest in which you would start out with a basic floaty-thingy and then more quests to get better stats ines over time. You had to kill this big robot, then the next phase you had to kill some roaming mob in some mountain area near Four Winds(?) dungeon?
I miss games with progressive spell particle effects. The more powerful and higher level the spell, the better looking the spell graphics became (more particles, more graphically instense casting), much like EQ had. However, AO took it to the next level as it had more progressions in terms of particles, not just the lvl 26(?) and 46(?) in EQ. I think there was probably 10 particle progressions by the time you hit lvl 200.