There was quite a variety of PvP game modes in the original game, some of which have been removed (Hero Battles, Team Arena). I personally do have fond memories of guild teams climbing up to halls first time. Which i feel would still be an amazing concept: good teams stay and get rewarded for doing well, the others reform at underworld.
How was the development of PvP back then (decision on mechanics) and how do you feel today about those game modes? I tend to believe theres been issues with GvG, Heroes Ascent, Random Arena, and Alliance Battle as stand-alones that led devs to merge these to a single game mode with less mechanics (as conquest is today in GW2) and WvW (which his completely different).