Well, I have tried CumpUSA lighting and they SUCK! so I wouldn't touch them. I then went too Xoxide.com and their lights are awesome, buth tubes, el-wire, and fans. Right now I have a tri-color fan in the back and a Thermaltike Cool Mod Fan on the HS. I kinda like it, but like you said, you want it subtle. I currently have 1 red and 1 blue fan ready to go into the two front fans, 1 green fan for the top, a red CCT, and some bright yellow el-wire. I think I have a busy weekend! But you said subtle, so I would go with maybe some exhaust fan lighting and maybe 2 intake fan lights on the front of the case.
Just my OVERKILL $.02!
Compy 1 (Brand New as of 2/7/07):
P5N32-E SLI w/ C2D E6600 at stock (for now)
Zalman CNPS9700 cooler
2GB Corsair DDR2800 @ 5-5-5-15 @1.9v
1x EVGA 8800GTX (stock)
1 150GB Raptor+ 250GB WD Internal SATA's
250GB WD Backup Drive
2x Plextor DVD burners, IDE
2x Plextor DVD burners, SATA
Audigy2 w/ Klipsch 2.1's
Black Silverstone TJ-07
PC P&C 510W SLI PSU
Dell 30" LCD