My first and only car for about 10 years in my 20s was a 1967 912 SWB. Beautiful car and very reliable when I drove it every day. Let me down a few times but never cost much to fix up. I wish I had held on to it now because I'd have made a fortune but I reached a point where I just wasn't driving it any more. My vote for favourite Porsche of all time would be somewhere between a late 60s 911 S, a 904/6 or a 356 Speedster.
I agree - love the simplicity of their shape and design from that period. An engineer friend of mine is restoring 4 911s at the moment for a couple of customers including a 1968 one. It's just come back from being acid dipped - some interesting holes in it at the moment he has to sort out!