From the list, I'd go with Bayonetta 2.
However, the only problem with discussions like this is, if it's done purely from sales, it's not necessarily which will be the biggest flop, as the games don't all have the same anticipated/projected sales.
I wouldn't expect a Wii U exclusive like Bayonetta 2 to sell anywhere near what Titanfall etc do. So even if it sold less, it could still be viewed that one of the other games was a bigger flop.