Spider -
I don't have a ton of experience (none with woodrail p&b), but I think Williams made the best games. Most included their 'running man' unit which really helps make the game in my opinion.
I have a '66 Williams Pitch and Bat. Not my favorite artwork (I think pre '65 are the best), but it does have 4 different pitches and a cool 'extra inning' feature which keeps you in the game longer if your opponent scored a lot of runs.
Pretty easy to work on (much simpler than a multiplayer EM) and a fair amount of the key parts (coils, bats, etc. are available). Plus some awesome pinsiders have custom made some parts - see the "home run" plastic on my game, not the original artwork, but I like it a lot better!