I like the free mods
its quite simple to mod it with software exploits only, there is a minor drawback to each of the two methods however
but this is how i started, I was playing backup games and homebrew software for free and never had to open my xbox (warranty intact!)
however I got a little tired of the buggy font exploit and PBL
which is why I now just flash the onboard TSOP
totally free and 100% of the features of the xbox (except you can turn it off for xbox live, unless you are like me and have a 1.0/1.1 xbox with 1mb TSOP)
tsop is easier than modchip even, just 2 drops of solder and flash away
www.xbox-scene.com is "the" site