I would say Memory or Mother for iDev, since Memory pretty much is Nessa but better, and Mother was one of the best sparring guilds after US stopped doing many of the GSTs. Also, don't forget that last GST, not many people really thought Nessa would get to the finals or even the semi-finals, but they managed to take first place in the iDev tournament, which means that any underdog has a chance at ranking high. As for mixed, I would say Alumni.