The Nintendo DS Lite is an instant classic. Period.
It's Brilliant. Absolutely brilliant. I don't know where to begin. Within five minutes of taking it out of the box I had the language switched from Japanese to English (mine was imported), the "Nintendo Wi-Fi Connection" up and running on my home network, and a Tetris DS game going with someone halfway around the world (in case you didn't know, Wi-Fi games are free). It's the perfect gaming device.
As I previously wrote, I held off on getting an original Nintendo DS because, well, it felt and looked like shit. The DS Lite is a complete revamp and upgrade -- it's a different machine entirely. The screens are insanely bright, the stereo sound is impressive and immersive, it's solid as a rock, and the form-factor and weight are very practical (it's totally possible to carry it in the pockets of your shorts or a sweatshirt or something).
Before my unit arrived I purchased Tetris DS and Mario Kart DS and have since bought Sonic Rush (amazing use of the dual screens; kind of treats them as a single "tall" screen) and Nanostray (a nice addition to one of my favorite game genres, the flying shoot-em-up). In the near future I plan to buy Meteos, Mario & Luigi: Partners in Time, 2006 FIFA World Cup, and New Super Mario Bros., which comes out in about a week (if the videos on the link don't take you back I don't know what will; IGN has just put up a glowing review). If you know of a game you think I might like and haven't mentioned, please let me know.
The early bird gets the worm
If you were at all interested in the DS, but hated its shortcomings, then there is no doubt that you will want the DS Lite. That said, if you plan on getting one when they launch in the states on June 11th (at $130!), you better get in line as soon as possible (read: pre-order) -- not to overstate the obvious, but this thing is going to be a huge success here (not only are all the DS-haters going to want a DS Lite, but those that actually have an original DS won't want it anymore once they see its latest iteration).
Keep in mind that you don't have to wait and can simply import it; I paid about $220 (including shipping) and Lik-Sang had it here in three days.
Still not convinced?
For those of you still on the fence, check out Cabel Sasser's videos comparing the DS Lite to the original DS and the Sony PSP (I've linked to these before in the bits); they're fairly entertaining and do a good job of highlighting the DS Lite's strong points.