favorite place for a last stand ?!

[quirkasaurus]

apologies if this thread has been done a zillion times before...

but for those times when your stack has dwindled to a mere
less than 4-5x BB and you know your next hand may well be
your last, what are looking for to push all-in PF with?
What situtation is your favorite?

any pocket pair?
any ace?
any suited cards?
ATC near the CO hoping for a steal?

following into the pot with whatever when 2 all-ins are
in front of you hoping for the miracle triple up?

all in when the blinds hit a specific player?
all in when the blinds hit a mid-stack? ( maybe 8xBB )