There are tons. Though looking for sneaky daggers to stab people with is really pointless unless you have enough tactical strength to use them. If you feel you do, here's a Blitz repertoire I used to follow:
White : Play 1.e4!
vs. 1...e5 : Danish Gambit. If you are a little conservative : Scotch or Goring Gambit
vs. 1...c5 : Smith-Morra Gambit. Strive for nice open kill-shot positions.
vs. 1...d5 : Transpose to the Blackmar-diemer gambit.
vs. 1...c6/e6 : Play the surprising 3.Be3?! after 2.d4 d5 and follow up with f3 and get into a similar K-side attack pattern as in the blackmar-diemer gambit.
vs 1...d6 : Play the Austrian Attack for the Pirc.
Black:
vs 1.e4 : 1...d5 and play the Nf6 Scandinavian. Lots of gotchas and almost always a nice open position.
vs. 1.d4 : Play the Budapest or Albin countergambit.
vs. 1.c4 : Try 1...b6, the English defence. English players I've faced haven't booked this on as well as the other lines.
I've found out that when playing in blitz matche's eithier it be me or my opponent that most of the time playing unpopular openings (bad openings) but still a little sound win's most of the time so my question is this can you name some opening's that are not popular or make your opponent really have to think ?