I think the above advice is very worthy. I'd avoid oddball stuff with little following for more happiness. Things like Opels, for example. Good strong clubs with good parts availability, easy maintenance and good highway manners. This may seem like odd advice coming from a guy with a Mini and a Fiat background. 
Corvair, Mustang, Falcon, are all good values and easy to live with. Anything convertible is an excellent investment but of course comes with more maintenance. Smaller domestics like Skylarks, Tempests, Larks, Ramblers and yes, Valiants can be affordable entry level cars. I would stay in the 1960s with OHV engined cars. Once you get back into the 1950s you start getting into 6v electrics and valve-in-block engines that sometimes have trouble with cooling and so forth.
BMWs are excellent choices. 2002s are nice but command a premium. You can get a larger, nicer car for not much more if you consider things like Bavarias, though you want to watch parts availability with some of them. The M-B's and Jags can be expensive to fix and can quickly rack up repair bills that will exceed what you paid for it. You've really got to be careful with those. I've looked at 'affordable' M-B's myself but, while sturdy cars, can have some components that will just absolutely break you should they fail. And, the performance of the older ones isn't usually that spectacular.
I recommend you go to car shows and talk to as many owners as you can about cars that may even just remotely interest you. Take your spouse too, if she'll tolerate it, and get some idea what cars she is attracted to. You will find when your partner thinks something is 'cool' he/she will be less likely to complain when you buy it/fix it. My wife is a fan of all 3 of my current play cars and helped me decide on the Mini over some other choices.