If you're talking plain jane GT500 vs. R/T, i'd take the R/T just 'cause i dont like the body of the GT500. Now, a GT350 on the other hand, i'd be all over.
OR
If it's the Elenor version of the GT500, well that's just a silly question. Elenor all the way.
I'd rather have the R/T to play with but those damned GT500's are becoming one of the most sought after Stangs ever. If you had one in excellent shape, it's like a retirement fund.
I would go with the R/T, it is definitely a true "muscle car".
My neighbor has a naturally aspirated '69 charger that run's high 9's in the quarter; the sick thing is that it weights 4200 lbs with the driver. I'll see about some pictures...
Wow.....those two cars probably are in my top 5 of all time.
Both engines have very nice styling and unique-ness too them. Both have power house engines in them (428 CJ vs. 426 hemi OR 440 six pack)......when they tested those cars back in the late 60's they were on crappy bias ply tires. If they had slicks on (or even the radials of today) then their times would improve dramatically. Even so (bias plys and all) they Charger still managed a high 13 1/4 mile and the GT 500 got a low 14. With traction the GT 500 would be an easy mid-low 13 second car and the Charger R/T might even break into the high 12's
The Shelby, no question about it for me. The Charger is cool and pretty tough looking, my buddy actually has one, but in my opinion you just can't beat the looks of the Shelby. Plus A Shelby can actually handle, something very difficult to get a Charger to do. There's also a plethora of aftermarket stuff for classic Mustangs. Besides, who cares what stock times were? Stock drivetrains suck for Hot Rods or toys.
But even dead stock vs. dead stock, I'd pick the Shelby.