Probably the biggest flaw in Pascal's wager
is that it does nothing to actually suggest that God
Ignore for the moment the other problems already noted: the vast quantity of gods to choose from, the possibility of a rationalist god who punishes irrational faith. Accept Pascal's argument as valid. What does it show? That belief in God has, mathematically speaking, a positive expectation. That is all. A skeptic, who thinks that the balance of evidence is that God probably does not exist, has been given no basis for honestly revising that opinion. "I wish I believed in God," he might say, "because of the reward that would bring me in the off-chance that He exists."
Sincere belief cannot be simply conjured out of thin air by an act of will. As an experiment, try to believe, sincerely believe, something that you're pretty sure is false: that 2+2=5, say, or that you're Napoleon Bonaparte. Can you do it? Probably not. At best, you can pretend to believe that 2+2=5, or entertain the hypothesis that you're Napoleon.
Pascal's Wager does not promote sincere belief. At best, it promotes a desire to believe, which can lead people to pretend that they believe when they actually don't. This may be sufficient for the purposes of the church, but it serves neither truth nor God.