I wanted to buy my sister a gift for her birthday.  I looked at the options there were and thought getting a DSlite would be the best option.  I was initially going to get her a 3DS but I don't think she would have a strong value for the features and I would end up buying only one game for her.

Anyways, I could get her a DSi or a DSlite.  There is a fair probability she will use the camera feature in the system and play around with the photos.  With the DSLite, that gives me a chance to buy her more games.  Here are a list of games I was looking at for her.

New Super Mario Bros.
Pokemon HeartGold
Plants vs Zombies
Mario Kart DS
Personal Trainer: Cooking
Sonic Classic Collection
Animal Crossing: Wild World
Tetris Party Deluxe
Harvest Moon
Warioware Touched
Dragon Quest 9
Namco Museum DS
Art Academy
Brain Age
Brain Age 2
Elite Beat Agents
Rhythm Heaven

The rule, I am trying to cap the price at $250, new preferred and extensive value.

Also, what color system should I get?

Have you listened to a certain podcast about Nintendo's great downloadable games only available via the DSi?

Lite man, it has a GBA slot.

Why not get Pokemon Black or White? But Pokemon, Harvest Moon, Mario Kart, and Animal Crossing are all great ideas for games.

If you can afford it, go DSi. I'm sure being a younger female, she'll enjoy having a camera to play around with. 

Unless she really wants to play GBA games, get a DSi

DSi.  I bet she will love the camera.

DS Lite.   

DSi. A funny camera AND great games? Must be Christmas!

DSi. That way she can download all those great My Notebook games!

Get her the DSi

My younger sister got one for christmas and she spends hours editing little pictures she takes on it and drawing in that flip pad thing.

Not to mention she's always on the internet on it aswell.

How nice of you to buy her something at such a price.

I would say Lite,
DSi has shop and camera, but Nintendo was too nice with the Shop devs for it to be worth it. ( There are exceptions though, I hope they arrive on 3DS too )

Definitely get her a DS Lite. There is nothing special about the camera and the downloadable games are poor for us, the "hardcores," so I doubt she would ever know they existed. (Though if you do get her a DSi, also give her an iPod stuffed with the NDX ;) )

You've got a good list going there. I would only say to get her Pokemon Black or White instead of Heartgold. Heartgold is great, but in many ways it does feel like a 11 year old game. I'd also like to recommend Mario vs. Donkey Kong. My sister is absolutely in love with that series.

Holy shit Plants vs Zombies is on the DS?

It's worth noting that the DS Lite has incredibly long battery life which helps make it a system that's convenient to just have with you all the time.