Had his 15 minutes
I think that his schtick worked great in Meet The Parents, where he's the poor schlub that can't win no matter how hard he tries. That worked for a few films, but it's old now. He's going down the same route as Adam Sandler, Bill Murray, and Jim Carrey. Jim Carrey can do drama though, the other three can't. When Stiller tries to be serious in a film he's got these emotionless, dead, psycho looking creepy eyes, and he just can't pull it off. His range, unfortunately, is zero.
Most of his films now seem half adlibbed, really immature, and just plain unfunny. His stuff seems old now, kind of like Bob Hope at the end. Sure, he's got some fans that will disagree, but I think he had his moment and just can't carry a movie anymore. We've yet to see, but I'm pretty sure that Zoolander 2 is going to be a huge bomb.
Snakes....I hate snakes