This varies, and it really depends on what you're looking for. On the one hand, some slot sites offer 7000+ games, but they may not have that one favourite of yours (although this is unlikely). On the other hand, some sites offer 900+ games, but they have every one you love. All that matters is that the slot selection is good, they have your favourites, and they are regularly updating their portfolio with new releases from a range of popular providers.