Was at a small tournament yesterday where first and second both were S&V (the 2nd place player was flying to IG-88s). Scum is popular, perhaps less so competitively due to it being new and people still being comfortable with their Rebel or Imperial lists.
If you're just getting started with the game you're going to need the base boxed set which comes with all of the maneuver and range templates as well as asteroids and the rules...most will recommend buying two of them, only do that if you have an interest in flying Rebels or Imperials...a scum player will not need more X-Wings or TIE Fighters.
For the faction you'll want "Most Wanted" for sure. not only does it provide 3 ships but also gives you dials and cards for two previous ships, the HWK-290 (previously Rebel only) and the Firespray-31 (previously Imperial only).
That being said, X-Wing is packaged differently than most miniatures games. There are cards that come with just about every ship that all of the factions can use and, while you can certainly play one faction, you're going to want to be picking up a bit of everything.
For example, in wave 6 (the current wave) you will find the "Starviper" which is a ship that can only be flown in a Scum & Villainy list but, there is a wonderful card that you can only get with the Starviper, "Autothrusters", that has a great benefit to Rebels and especially to Imperial players who enjoy flying Soontir Fel (gilding the lily).
The good news is that it is still cheaper than other miniatures games (has been for me anyhow) and you need not worry about painting & assembling models or gray areas in the rules. X-Wing is a very tight game and the community is fantastic.
One thing is for certain about X-Wing...while there are popular "net" lists that are great, there is certainly more of a variety of lists compared to other miniature games I have played. So, to shwnlyns point...fly what suits your play style.
