Most common for "over-counter/under-cabinet" lighting that I've installed is fluorescent. Xenon and halogen are more commonly used on top of the cabinets (sort of a "cove" lighting effect) and under the kick of the bottom cabinet.
Fluorescent fixtures specifically made for undercab lighting are available just about everywhere, even at the big box stores. They're pretty inexpensive and virtually unseen when installed properly.
Various techniques for installation is to either install the outlet inside of the cabinet or above it, using plastic wire channel where the (factory installed) cord may be visible within the cabinet - or - run MC into the drywall where it cannot easily be seen and into a box within or above the cabinet with a blank cover.
To make less of a fingerprint on the cabinet when using the factory installed cord, cut the cord cap off of the factory installed cord and run it to the outlet through the smallest hole you can get away with in the bottom of the cabinet. Run it through the wire channel and cut it to length, then install a new (usually ungrounded) cord cap plug, giving just enough slack on the cord for easy plugging and unplugging for future service.
The fluorescent fixtures can be interconnected easily with an MC whip. The reason I favor these over the xenon or halogen strips for undercab is that they require no transformer. With overcab and kick lighting it's easier to install a transformer somewhere that it will be rarely seen.
Good luck!
