Welcome! I'm sure there will be many here that will chime in and give you excellent advice. Take some time to peruse the various threads others have started looking for "the best games under *insert arbitrary price*"
My advice to you is to find an arcade, and play some games. Find out what you like, what you don't like, and go from there.
Generally, a William's or Bally game will cost the most compared to other manufacturers. They remain popular, and hold value well due to their generally good gameplay and ease of finding parts and repair support.
Gottlieb games are a bit of a black sheep. You can find them for much cheaper than Bally or William's titles. They have a different feel to them and collectors generally dislike their gameplay or rules. Personally, I think they're great games, and offer tremendous value. Beware: Games produced up until ~1989 or so have reliability issues due to hardware flaws. Once corrected, however, they are very reliable machines. Games after 1989 are notorious for being absolutely rock solid and bullet proof. Gottlieb certainly learned from their mistakes.
Data East games fall in between Gottlieb and William's/Bally games, in my opinion. They used the same hardware as William's did at the time, have good layouts, but people often complain about them all having similar rules, and a relative lack of depth in gameplay. However, their themes, artwork, and sound direction is very good.