Games that use X-Y monitors are definitely some of best arcade games ever made. Vector graphics allowed the programmers to do things that just weren't possible on the raster hardware of the time. Vector games had smooth scaling, 3-D graphics, and complex rotation and scrolling effects that nothing else could even come close to. But all that smooth vector goodness, wireframe 3-D, and stick figure cows came with a price, that price was the X-Y monitor. But I will get into that a little bit later.
The first vector games were done in monochrome, and most of them didn't really push the capabilities of the vector hardware. Some games (like Asteroids), could have easily been done with normal raster hardware. The first vector arcade game was the 1977 version of Space Wars, which was a copy of the much earlier computer game of the same name. Star Hawk, Speed Freak and the absolutely horrible Barrier came soon after. In 1979 the vector industry really started taking off with Lunar Lander, Asteroids, Tail Gunner, Warrior, and the ill-fated Sundance.
The era of the color vector game began in 1980 with Tempest, which is still said by many people to be the greatest game ever created. The color vector era brought such technological marvels as Star Wars and the amazing Sega color vector titles (Space Fury, Zektor and several others). The vector era finally came to an end in 1985 with the releases of The Empire Strikes Back and Vertigo.
Vector games are the favorite of many hard-core collectors. Cinematronics titles seem to be especially sought after. The average working vector game currently sells for prices from $500 to well over $2000. But there is a major problem with all of them. That problem is the X-Y monitor. Vector arcade monitors went out of production almost 20 years ago. Most of them were problematic even when new. For example, Sega vector monitors were known to catch fire, and most Sundance machines shipped with a defective monitor that blew up as soon as it was turned on. Now fast forward to 2002, and what you have are a bunch of monitors that are constantly being repaired, and hacked together with an ever-decreasing supply of replacement parts. The price of a working X-Y monitor has constantly increased over the last 10 years, and it is continuing to go up.
I must admit that I secretly harbor fantasies of having Star Wars, Speed Freak, and Asteroids all sitting side by side in my gameroom. But X-Y monitors are like ticking time bombs. There simply are no replacements, and eventually they will all fail. The more you read about arcade games on the internet, the more you realize that most vector games are already dead or dying. The arcade newsgroups are full of posts with people who have vector games with dead monitors. If you browse through the auctions at eBay you will probably find 50 working vector boardsets listed for every working X-Y monitor.
My suggestion is to stay away from games that use X-Y monitors. That Asteroids machine is going to die on you eventually, and when it does, there will be little you can do to fix it. You can only install so many Zanon upgrade kits, and locate so many NOS flybacks before you are stuck with a monitor that refuses to respond to further repairs. Raster games (like Dig Dug, Kangaroo, Missile Command, et cetera), can almost always be repaired, and they still make the monitors. I suggest spending your money on them instead. A classic arcade game can be a big investment, and X-Y games are an investment that is sure to fail.
Complete list of vector titles.
Some of these games were bootlegs, some were widely released, and a few were merely prototypes. Most of these games still exist in some form or another. But not all of them, a few have been lost to the ravages of time. While others (like Sundance), were defective from the very start, and only exist now because they have been recreated from parts by very dedicated collectors.
I am fairly sure that the above list is complete. But I could be wrong, maybe there is something that I have never heard of, or perhaps the vector community will discover some long forgotten prototype game in a warehouse. Either way, feel free to message me with additions to this list.