In this hobby, we are all eventually "Outta Space."

1970 Bally Expressway is a great choice. However, the OP is not likely to find an ultra-scarce Bally Balls-a-Poppin and he specifically stated that he disfavored 2 inch flipper games.

Bally Skyrocket is fantastic, albeit pricey at the moment (approaching the $3K mark for an unrestored example).

In my opinion, the best 3 inch flipper Gottlieb wedgeheads, which are somewhat available and affordable, are Volley and Atlantis. Volley is drop-target nirvana.

I might be willing to sell my collector quality Volley. Just be sure to get a true production Volley as opposed to the cheap painted chipboard playfield Volleys out there.

I also love Blue Note (very low production), Strange World, Hit-the-Deck (low production) and Big Hit in my line-up, all 3 inch flipper titles. But, the 1st three titles (BN, SW and HtD) are commanding high prices (the last two Strange Worlds sold for about $3,800 and $4,500 and HtD and BN have traditionally fetched high $$$). Big Hit, while still affordable, has become hard to find.

Succinctly stated, I recommend Gottlieb Volley, Gottlieb Atlantis, Gottlieb Big Hit and Bally Expressway as the best bang-for-the-buck games, which are reasonably available. None will be super easy to find immediately. Nevertheless, these titles do appear for sale sporadically in the $700 - $1,800 range, depending on condition. These CQ wedgeheads will fetch north of $2K, especially Atlantis, but closer to $2K than to $3K generally. These are fantastic games, with smart playfield designs, pleasing shot vectors and attractive art packages.

All will probably hold their value or escalate, based on a 35 year trend and in light of recent EM price trends. Been in the hobby for over 3 decades. That's my 2 cents.

You include 2001 (great game), forgetting that it's a 2 inch flipper game. In the 4 player category, I recommend Gottlieb Surf Champ. Joker Poker EM gets my highest vote; but, alas it's another scarce title.

In the zipper flipper category, I like Surfers, Rocket III, MiniZag, Fireball and multiplayer Cosmos.

My 1951 Chicago Coin Thing woodrail has been even more reliable than my Gottlieb woodrails. I have barely had to adjust anything in two decades, even after months of dormancy.

Enthusiasts seem to denigrate CCM sixties and seventies era games, more than those of other manufacturers. CCM had a few good titles during that period, perhaps not enough to garner a dedicated following.

For someone, like the OP, simply seeking to add 4 EMs, I wouldn't write off any manufacturer and certainly not for reliability reasons. All manufacturers can perform well in the home environment, when correctly tuned.

You can't go wrong with Gottlieb, Bally, Williams or Chicago Coin, as long as you choose the right titles. Gottlieb does have the edge on parts availability, though, by virtue of Pinball Resource and Steve Young's willingness to offer telephonic advice.

We're all thinking it; but, nobody has said it. So, I'm just going to let it out.

*Your guests will flock to your EM games.
*Soon, you will fall in love with EMs.
*Before long, you will look forward to repairing, restoring and hunting down EM games.
*In short order, you will be replacing your solid state and modern machines with EM games.
*It's just a matter of time before EM games will take up residence in your living room, bedroom and kitchen.
*By late autumn, with excess caffeine in your bloodstream, you will dominate the Pinside EM threads, adopting O-din's old cigar-smoking bulldog avatar.
*By winter, in desperate need of a shave, and with a month's worth of unanswered emails, you'll be wondering whether your family really needs a bathtub or whether that space will be better served by an EM.
*By spring, you have legally changed your name to Mr. Score Reel and have reduced your verbal responses in human-to-human conversations by perfectly mimicking the sound of a Gottlieb chime unit.
*Your wife has taken the kids, the cat, and your prosthetic leg to a hotel. You haven't noticed.
*Fast forward to next summer, a year hence, having purchased the largest warehouse in your state, and having acquired every desirable Gottlieb, Bally and Williams EM title, you will start a thread entitled: "What Are the Best Inder and Sonic EMs?"

Just kidding (not really).