Phantoms have always been a good choice. If you can find an old SL-68II they usually aren't too pricey and are great intro markers to open pump play (I have both as my go-to markers, although the SL-68II is set up for 10rd play)
I suggest that you look though this forum for threads regarding gun recommendations. There's a wealth of information, and you'll get a good idea of what features and characteristics are important to different people. The stickies are a good place to start.