i think Ratchet and Clank will have better first week numbers, I will even go as far as saying R&C will sell better than QB on both platforms in lifetime sales.  Let me know what you guys think.

Ratchet and Clank. Classic PS franchise on the bigger userbase, plus all the attention it will get when the movie comes out. It has all the advantages to outsell QB both in first week and in total sales.

Hard question, because I think Dark Souls 3 will eat a huge chunk of both their sales. I'm going to go with Quantum Break.

Ratchet & Clank (but it will be close imo)

R&C.

R&C was top20-30 for a very long time, before QB was even in the top 100 I think on amazon.
QB never made top5 before it released, and never hit #1.

R&C has been #1 on amazon for like 13 hours or something now.

Why I think so?
#1 its a platformer, dont see those that often, theres a fanbase that misses them (QB wasnt just another shooter but..)

#2 the price differnce. R&C is 40$.

#3 install base of PS4 is likely double what the XB1's is.... World wide that will matter.

#4 Nostaliga + family friendly. R&C can hit a larger audience.

Well Ps4 has a bigger userbase and ratchet and clank is a classic franchise so I'd go with Ratchet and Clank even though I'm hoping QB will outsell it.

Ratchet and Clank easy

QB
R&C only has USA in its FW

Ratchet.

Bigger user base and a lot cheaper price.

QB, more mainstream genre, although, PS4 has double the user base.