Rans Rockst (Retro rocket) Rans Enduro Sport (Retro racket) Hase Kettweisel Tandem (redundent recumbent), Merin Bear Valley (The gopher).
I'm significantly older than you and I've got several bikes to choose from.
If I had to limit myself to one bike, it would be a road bike. If I were buying a new road bike for myself today, I think that I'd look at the bikes like the Trek Pilot that have higher handlebars. I like my handlebars to be around 1 or 2 inches lower than the saddle.
I just road my new Trek Pilot 2.1 for the first time today. It was my very first ride on a road bike. I will be 54 iyears old in another week. I have been riding a comfort bike for 6 months. Boy, the Trek is really smooth and fast! I was worried about the new riding position, but the Pilot's gemeotry was very good on my back. Also, I was afraid of the new seat. I am used to a large gel padded seat on my comfort bike, but my new raod bike has a Trek CRZ saddle with a cut-out channel. It is a small saddle compared to what I am used to riding. The new seat was great! I did not hurt at all.