QUOTE(Maximum_Joe @ Feb 22 2013, 20:08)

In what sense? Cost?
Well I'm not sure what Ichy meant by surpass so I went with PL.
In the sense that they'll reach the highest level with a realistically attainable number of crystals. Although some monsters have a higher level cap than Humonoids, nobody will ever reach those levels due to the cost. In terms of what's achievable Humanoids are the best for upgrading.
It looks like Anthropoids are actually the second best. If Eila were an Anthropoid and I'd collected the same number of crystals she's be the same level as she is now, but would be 2 levels lower when I do the six Element Resistance upgrades required to reach 1501.
If she were a Beast she'd be 5 levels lower than she is now.
If she were a Mechanised she's be 125 levels lower than she is now.
If she were an Elemental she's be 131 levels lower than she is now.
If she were a Sprite she'd be 187 levels lower than she is now.
etc
Furthermore, the level difference would continue to grow the more crystals you collected. The only time other monster types would start to pass Humanoids would be when you got into the trillions of crystals. Since nobody will ever get trillions of crystals (well, they might if the current rate of devaluation continues) Humanoids are the best for reaching high levels.
That's rather fortunate since I only picked Humanoid because it was the most appropriate type for Eila.