I bought all 4 games:
Destiny - purchased digital guardian edition, huge letdown. On the other hand I've put in 100+ hours into the game, the PVP was really fun for a while and its a good escape if I just want a quick 1 hour gaming session. Overall its more a disappointment in what the game COULD have been (PVE single player campaign was beyond wretched), it is a good framework for future AAA franchise titles though in terms of having a rock solid multiplayer environment that is basically like an MMO without a sub. Just needs a much better story.
Halo MCC - haven't played yet, but I bought it mostly to play the SP campaign and my understanding is that works fine. Never played more than 2 hours of halo 1 (kid born that month).
Driveclub - worst game, I preordered and asked for a refund after a week (and got it). SP was fine but MP was a complete joke, something really shady about Sony wanting to put it out for free on PS+ but never doing a public beta to ensure it can handle millions of people. Really, really, really disappointed in Sony here.
AC Unity - I love the AC series, pre ordered the day it was available. Was ok, SP campaign was pretty lackluster although Paris was amazing as a setting. Bugs and glitches ruined the game. I did finish the SP campaign (didn't bother with most side stuff) in ~20 hours and traded in the game, already forgotten almost all of it. Not great when the most memorable parts of your game have nothing to do with the main story (Rifts, Murder Mysteries). End of the day I would have rather re-played AC4 than played AC5.
I'd put Unity and Driveclub as the most disappointing game and technical, since they could have made Unity 10x better with six more months work but choose to hit the deadline instead. Driveclub was just an utter mess.
To me its really interesting contrasting Destiny and Unity. Destiny clearly said six months before launch "ok all we are doing now is making sure the game works flawlessly, we are not going to implement any more features". Whereas Unity clearly focused just on hitting the launch date and didn't scale back anything or really work on polish. I like the scope and ambition of Unity, vs the "timidity" of Destiny. In the end though both games failed for similar reasons: not paying enough time to make sure the single player experience was meaningful.
Fortunately I think GTA 5, Dragon Age 3, Far Cry 4, and to a lesser extent Smash and Bayonetta 2 have erased a lot of these bad feelings for me. GTA5 especially is such an amazing game, and the remaster shows a lot of love and labor poured into it.