I'm exactly the same way - my ipod is my personal soundtrack so working out without it is virtually impossible.
Disclaimer: Being 24 and from Trinidad and Tobago- I have really eclectic tastes so don't judge me - ha ha! Some of the songs you may not even know but check them out - it's worth it.
1) The Pretender by the Foo Fighters - great way to start!
2) All my life by the Foo Fighers
3) Are you gonna be my girl - Jet
4) Bleed it out - Linkin Park
5) Bodies- Drowning Pool
6) Boom - Damien Marley
7) Breaking Dishes - Rihanna
8) Bubble Like Soup - Timberlee
9) Defence - Machel Montano featuring Pitbull
10) Calabria - Enur (song from that Target ad with the two college girls dancing around)
11)Renegades of Funk - Rage against the Machine
12) Chop Suey - System of a Down
13) Closer - Neyo
14) Gimme More - Britney Spears (say what you will but it's a fun song to work out to)
15) Crushcrushcrush - Paramore
16) Bamboo Banga - M.I.A
17) Du Hast - Ramnstein
18) Push it - Static X
19) Faint - Linkin Park
20) Firestarter - Prodigy
21) Get Free - The Vines
22) Girlfriend - Avril Lavigne (great running song - if you run)
23) Given up - Linkin Park
24) Guerilla Radio - Rage Against the Machine
25) Hey Ya - Outkast (Andre 3000)
26) Hold it - Faye Ann Lyons
27) Just Dance - Lady Gaga
28) Maghelena - Sergio Mendez
29) The Middle - Jimmy Eat World
30) Paralyzer - Finger Eleven
31) Please don't stop the music - Rihanna
32) Toma - Pitbull
33) Womanizer - Britney Spears
34) When I grow up - The Pussycat Dolls
I also listen to a wealth of bellydance music and tribal drum beats - those really get the blood pumping.
So there you have it Happy Sweating everyone!
Got to get off this merry-go-round