[gguruusa]

You might ask yourself "What do each of the alternatives (stock/custom/kitchen) offer?"

Stock
If you have to talk to your carriers technical support or you need warranty service, this is the ONLY choice. Technical support doesn't know and doesn't care to learn your custom rom. They certainly won't help you fix its issues. Installing a custom rom voids your warranty, so flash stock if you need warranty service.

Stock roms sometimes fix very strange custom rom issues. We don't know why this is. If your device has strange hardware like problems, try flashing stock...it might just fix it.

Custom
Less/No carrier crapware.
A few bugfixes.
Unless it's Clean, some additional Apps
Custom themes and dialers
Sometimes built on much newer OS cores - new features bring new bugs, so this can be a mixed bag, but generally its a feature.

The primary difference between Custom roms is the theme, the carrier, and the OS base - custom roms of the same vintage run pretty much the same, regardless of who cooked them.

Do Not install Custom ROMs for carriers other than your own on your phone.

Kitchen
Why settle for someone elses idea of what's good when you can have your own?
Works with all carriers
Wide selection of apps/tweaks to choose from
Wide selection of OS bases to choose from, from stock to latest and greatest
Foreign language support (coming soon)
RUIM card support (if you need it)
Multiple device support - take your configuration with you to your next PPC!
Can bake YOUR settings in. Never have to set your phone up again!
Takes about 20 minutes more time than a premade custom ROM, and three times the hard drive space.
Takes a little more effort to make a nice theme
Can be intimidating because of all the choices available - just remember you don't have to choose anything more than your carrier.