first of all, anyone who thinks it is fair to compare these two media mediums (alliteration is always fun) is probably an alcoholic.  i will use analogies to show how it is unfair to compare home consoles to handhelds.  would anyone here agree its fair to mp3 players or ipods to home stereo systems?  i think not.  how bout portable dvd players to home dvd players or same for blu ray players (not completely sure if they have portable blu ray players yet, but i cant see why not)?  one last analogy, compare an ipad or xoom to a custom built, high-powered desktop pc.  i think you all know where i am going with this.  through these analogies, one can easily see how saying the nintendo ds is a better selling console than the ps2 is not only misleading, but completely unjustified.  they are two completely different ways of playing games but are both great in their own right.

Put it this way.I have 3 kids and the day I bought 1 of them a GBA is the day I bought 3 of them a GBA. The day that we got 1 of them a DS we got all of them a DS. They have always shared software as well.

That is not how consoles work.

Call me an alcoholic but......a handheld system is just a system with a display , battery source and inputs either on or inside the system.

You can compare whatever you want.  How relevant you think the comparison is up to you.  I think comparing handhelds and home consoles is relevant so I'll do it.  You don't, so ignore the comparison since you don't think it's relevant.  It all subjective and is up to personal ideologies.  If I want to compare the rate that grass grows to the effects of paint thinner in a person's eye I can just like you can find the comparison irrelevant and ignore it. 

I just don't understand why people take this debate so seriously.

Edit:  Forgot to mention how dumb it was to call folks who disagree with you alcoholics.  It's a meaningless statement and shows little effort was put into the OP.  Call me retarded or an idiot, that would make sense but alcoholic?  You must be a vegan.

they are comparable they both are consoles technically. Anyway once the ds passes the ps2 im sure it will be considered the best selling period regardless if its a handheldor not

while i agree they're not comparable because I honestly believe they go after different demographics and have differences purposes and types of games....I disagree with your whole post. Bad to average analogies and insults sprinkled around are not needed lol.

I also would like to point out for example how I have owned at least 1 home console per gen since the nes and I have never personally bought a handheld. If the two consoles were so very similar, I (as well as others) would not have such an affinity toward one and not the other.

Or another example would be simply how certain games fit the portable style like pokemon while others fit the home console style.

EDIT: i came in hoping for a nice and well-thought out OP arguing this side of the debate as many are against this train of thought.

I still believe they are not comparable. You can't have 2 people on one portable device. But you can on a console.

All this  just to take from the DS the title of "Best Selling Console Ever"?.

NGP will have a similar power to that of the PS3, so, we can say that handhelds are capable of playing the same software that a home console does. The only difference is the size of the screen, nothing more.

If by the chance you're referring to my post, I wasn't talking about the power of the systems and their abilities to play a game based on it's graphical needs. I'm talking about how you'll never see some portable games on home consoles and vice versa because of their respectives game styles and who they attract. Of course there's many kinds of games that fit nicely on home and portables consoles.

Edit: I do agree w/ you though that I assume the OP brought this up so that the DS wouldn't be called the best-selling console (in his mind anyway). Debating this for that purpose is pointless.

I agree it's unfair to compare the two. Portables are more in line with personal devices, for example in my household, we all have our own DS (4). Home consoles are for the most part, one per household (we have one PS3 and one 360). So in my case you have a scenario where the DS outsold the home consoles 4 to 1.

Again, portables are personal devices and thus will always outsell home consoles. Apples to Oranges.