Top 3 jarls who wants to beat you up for killing your wife!

I think for that to work, you'd have to kill her in three different holds at the same time. Of course there is that crossroads below Fort Sungard (?) where Whiterun, Falkreath, and the Reach all sort of meet each other... I suppose if you had to chase her around a bit and managed to assault her in all three holds in the process you could incur the ire of all three Jarls.
OTOH, I don't think Igmund would beat you up for it anyway. He'd just promise you free wife-killing privileges in the Reach and then hand you over to the Empire for your beating after the [censored] hit the fan.
Balgruuf would pretend not to want anything to do with the whole "punish the wife killer" controversy, but would really be in favor of someone else beating you up as long as it doesn't happen in his city.
Siddgeir would probably want to beat you up, but only because your wife was running a very profitable skooma smuggling operation under his protection and now he's no longer getting his share of the profits. However he'd have to send hired thugs to dish out the justice because he's got more important things to do with his time. That throne of his ain't gonna slouch on itself for 16 hours a day, amirite or amirite?