Yes, a good number of them are similar superficially, but most sport subtle design differences that keep them from looking like mirror images of one another.
Given all of that, let's take a gander at the six dual-screened handhelds Nintendo has supported since 2004 and then grade them in terms of best to worst (or most to least appealing).
For starters, here's the original Nintendo DS:
Two years after the system above was released, Nintendo followed it up with the oh-so-svelt DS Lite:
The similarly sexy DSi (striking a pose below in hot pink) hit the streets just two years after that:
And, then, of course, there's Nintendo's first jumbo-screened portable, the DSi XL, launched in 2009:
Everyone has seen the company's latest dual-screened product, right?
Finally, there's the 3DS XL (3DS LL if you live in Japan), which will land on store shelves later this month or next month, depending on where you live:
As for which design I like best: I'm going to go for the DS Lite and DSi this time around--due to the fact that they're sleek as can be but also completely portable (something that can't quite be said for their successor, the DSi XL/LL).
That said, I'm also pretty fond the original DS' design. I know it's by far the most toy-like of all of Nintendo's clamshell handhelds, but I've long had a soft spot in my heart for it. (Now if I could just find a "candy pink" one in like-new condition...)
Anyway, those are my thoughts on this completely unimportant matter. What are yours?