2. Co-op is the way to go.
I've played Monster Hunter 4 Ultimate in both solo and co-op modes, and I think the latter is ultimately more enjoyable.
Of course, battling an enormous creature one-on-one can be exciting for some, but there's something more thrilling about banding together to take down a merciless, hulking behemoth. Everything from coordinating traps to collectively walloping on a stunned Daimyo Hermitaur created this very satisfying feeling of camaraderie with fellow players.
That camaraderie manifested itself at New York Comic Con. High fives were had among my teammates after we took the monster down within the allotted 15-minute time limit.