I agree that what you want to use the shop for can quickly narrow down the tools that will be useful and can fit into the space. I don't know if this was mentioned, but if I had just one saw it would be a bandsaw. A bandsaw is useful for almost any type of woodworking. I find it an essential tool for woodturning, making jigs and patterns, resawing, repairing things. The 14" saws these days seem pretty good and many can cut 12" thick stock or green wood.
JKJ