I imagine most people here would take the cup which I 200% understand, since following the teams for decades without winning anything would make a win a very big day. CL qualification through the league is arguably more difficult and has A LOT bigger impact, but its perhaps not something that gets you dancing on the streets.What if the options were:
Qualify for the Champions League
Win the FA Cup
Champions League would be really massive though. £100m in the bank account and going to Bernabeu or Camp Nou or something... which is what all players want. Would make it a lot easier to keep the best players and sign very good ones.