Destiny - Creators of Halo
Titanfall - Creators of Call of Duty
Now both are new IPs with new publishers. The 2 biggest publishers in the world. Both require online connections. Both are cross-gen (their design is anchored down by current gen). Neither looks particularly great in the graphics department, although I would give Destiny a slight edge due to art style.
Destiny looks like the next Halo.... Titanfall looks like COD with mechs.
This time around, the Halo developer Bungie is multiplatform while the former COD developer is exclusive (timed, most likely). Both will get HUGE marketing.
Destiny will be on PS4, PS3, Xbox One, Xbox 360... with exclusive content for PS4/PS3 and an advertising deal with Sony.
Titanfall will be on Xbox 360, Xbox One, and PC.... with a PS4/PS3 release sometime down the road. Probably a year after it's released, like Mass Effect 2 and BioShock.
Which franchise will be more popular now? Which will sell more? Which will get better reviews?
IMO they are both a little overhyped. Some have called Destiny a Halo/Borderlands mash up.... Titanfall is really only being hyped because its exclusive. Lets be honest, if it were multiplatform it wouldnt be getting nearly as much hype as it is. It's basically COD with mechs, and no single player or co-op.
I know its crazy, but a lot of people actually play COD's campaigns. They were also critical in creating hype and "controversy" for COD, with edgy chapters that had an option to be skipped by players, and Michael Bay set pieces.
Not having single player is going to hurt Titanfall a little bit.