I've always heard the Petrov Defense is a drawish opening, but in the hands of a suitable player - such as Anand - Black can manage to lose in 6 moves!
http://www.chessgames.com/perl/chessgame?gid=1018015

In league chess I'd sometimes play 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6

now they expect 4.Nf3 Nxe4 5.Bd3 etc.  but you disappoint them with

4.Nc4 Nxe4 

this works best with quiet players who are not tactical hotshots and are hoping for a draw - you are getting them out of their comfort zone.

You can play 5.d4 d5 6.Ne3 and at that point Black often starts looking worried - what happened to the drawish opening they expected? If they're prepared they play 6...Qf6 7.Qe2 Be6 8.c3 Nc6 9.Nd2 O-O-O 10.g3 and you have an unbalanced and interesting game.

You can also play 5.Nc3 Nxc3 6.bxc3 and Black has to think quite carefully and be prepared for a fight - White has a good score from most responses here.  e.g. 6...g6 7.d4 Bg7 8.Bd3 O-O 9.O-O and Black has to defend carefully.

On a slightly more serious note, a line like 1.e4 e5 2.Nf3 Nf6 3.d4 Nxe4 4.Bd3 d5 can be fun and undrawish against the Petrov, Nxe5 is often played but 5.dxe5 is also good

Here is a better Anand game along that line

After 11...O-O 12.Qh5 it's hair-raising stuff

and one with 5.dxe5

There are various other alternatives you can try and I hope this inspires you to research some of them and then you will no longer have to grumble: "Oh no, not another boring Petrov!"