Pipo monkeys are some of the coolest characters ever and Ape Escape 1 is a certified Sony classic, but the rest of the series never had the same luck. AE2 kinda sucked, and while AE3 is probably the definitive experience of the series, it was a already bit tiring by that point.
An Ape Escape 4 developed by SIE Team Asobi is a dream game of mine, tho.