Oblivion Remastered has given us all an excuse to return to Cyrodiil and re-experience just how weird the guild system is. There are no restrictions on how many you can join, so you can work your way up in every faction in the region without consequence. Fans are split on whether this is a good idea, but at least it saves you a replay if you only want to make the one character.
However, just because you can join them all as a single character, that doesn't mean that players are actually doing that, and they certainly aren't completing the guild questlines at the same rate. Looking at achievement stats, it seems that the Fighters Guild is the least popular questline, whereas the Mages Guild is finding it very easy to recruit.
Oblivion Remastered has an achievement for joining every faction, and further achievements for advancing through their respective quests. This means that we can see which guild is attracting the most members, and which one has the highest completion rate.
In terms of getting people to just sign up, the Mages Guild is in the lead across every platform. After that, it's the Arena, and then the Fighters...
