Studying the IPDB and going to shows has taught me that the most important aspect of a good pinball machine is its fundamental geometry. A good game has a variety of angles, things to shoot for, and ball flow. However, without satisfying goals and challenges to complete along the way... all of that is wasted.
For example, Flip-A-Card and King Of Diamonds have terrific layouts... but the goals are too simplistic: Light everything up and win. Repeat. Point values don't correspond well with risk and don't vary much across the table. Because of this, they end up appealing more to that OCD "gotta win a replay" feeling rather than because the game itself is fun. Which A LOT of Gottlieb's suffer from... Buckaroo, MIBS, Sweet Hearts, geez, tons. Which is one of the reasons I like Bally games so much. They tend to emphasize play over "completion".
My only woodrail is a '52 Gottlieb Crossroads. I've only played a dozen or so woodies, but so far this is my favorite. Good shot angles and no gobble holes... but there are traps... which will either work with or against you depending upon when you capture the balls. Failing that, you can try to chase the bumpers in sequential order and/or go for the 100,000 point pops when lit. It's got good artwork, flow, shifting goals, and shot geometry. Fun for the "completion" factor as well as the play. So I guess I can recommend at least one....
Crossroads plays more like a machine from the 60's than the 50's due to the side slingshots and long return lanes. Ball flow is consistent and always in motion. In the video above, I'd have let the last ball drain to earn that special!