Pascal's Wager makes one
fundamental assumption that is
incorrect. It assumes that the choice is between not believing in
god and
believing in god. It assumes one description of god.
There are MANY gods that have been, and currently are, followed. If we add each god into the wager, we soon run into thousands of options, and they cannot all be followed. It follows that the only choice is to believe in the god with the worst punishment for disbelief, or to totally disregard the wager as flawed and irrelevant.
Also, there's the fact that it is not free of cost to believe in God. First, whatever religion you decide to participate in due to the wager will have rules and restrictions for you to follow, actions you must take, and the like. You will end up spending time for religious rituals that you could be doing other things with. You may spend money that may be better donated to charity that will help people, or spent improving yourself (especially in the case of Scientology). And you'll suffer intellectual costs, as some things you'll disbelieve due to religion, or the like.