It varies for depending on what background I choose for a game. For example, I'm running an Honorverse style game at the moment with two counter-missile types (because I realised the combat settings won't automatically use size 2 missiles as countermissiles and had to switch to size 1), four different sizes of anti-ship missile depending on the size of the launch platform (size 5 for destroyers, 10 for heavy cruisers and so on), with the three larger sizes then coming in a multistage format to accomodate 'canister' rounds of size 1 countermissiles.
On the other hand, my latest game has around four missiles, size 1 for anti-missile/fighters, size 2 as a lightweight anti-ship missile (playing on maximum tech as an Andromeda Ascendent setting), and then two size 10 missiles, one with over one thousand million KM's range, the other trading about three quarters of that range and a chunk of warhead strength for an extra 60,000 km/s. I might end up reworking that one in fact since it's got less strength than the size 2 missile!