Do an internet search on Dr Pepper clones and you will find there are dozens of them! Collecting DP clones could easily be a subset of someone's main collection. Thus far in my collecting adventures, I have accumulated ten clones.
Top row: Dr Pop, Dr Phizz, Dr. Wow, Dr Shasta, Dr. Choice
Bottom row: Dr Thunder, Dr. Chill, Dr Vess, Dr. K, Dr. Topper
Oh, and if you get a headache from the caffeine, I recommend a call to Dr. Brown...