I don't know what you're considering a low score, but even the best machines are going to have some people who have negative things to say about it. I personally can't think of a single way I'd improve Twilight Zone, but there are lots of people out there that can't stand to play it. If you're looking for a first pinball machine, and maybe you aren't looking to buy many down the line, I'd go for a good DMD machine.
There are quite a few DMD (dot matrix display, which means it has the little screen with animations on it) machines out there that aren't too expensive and that parts are readily available for if you have issues. Some of the Data East machines are on the economical side, such as Jurassic Park, Teenage Mutant Ninja Turtles, Back to the Future, Hook, and The Simpsons that are pretty fun. My favorite Data East game is Jurassic Park, and I think it stands up with any other game out there, really. It can be had for around $1,250 or so, which is good because it's a game with a long staying power.
Data East games are a little cheaper because pin snobs often think you have to go Bally or Williams, but it's not always the case.
However, if you choose to shy away from DE, and that's fine if you do, here are some really fun Bally/Williams games that aren't expensive and are probably pretty easy to track down:
- Fish Tales
- White Water
- Dr. Who
- Junk Yard
- Bram Stoker's Dracula
- The Getaway: High Speed II
- Whirlwind
- Road Show
- Earthshaker
Just keep looking around and you'll find something.