Frontline by Pillar is possibly my favorite ever.
For rugby I don't see how you can go wrong with anything by Dropkick Murphy's

Heres what I played before every hockey game this past season, in order.
Far Behind - Candlebox
Lonely is The Night - Billy Squire
A Whisper and a Clamor - Anberlin
Cemetary Gates - Pantera
Cowboys from Hell - Pantera
Misery Business - Paramore
Blue Monday - Orgy
Frontline - Pillar
Down - Socialburn
Shinedown - Godsmack
Sabbra Cadabra - Metallica
HELLYEAH - HELLYEAH
These Lights - The Forecast
The Warrior's Code - Dropkick Murphy's
South of Heaven - Slayer
Dead Skin Mask - Slayer