In all honesty, I own all three systems, a DS, and a PSP- and PS2 is my favorite. I have very specific reasons why I like each console and I know everyone else does too. However, when other people's opinions differ with mine I don't chalk it up to ignorance.
Just to add a few things on what each console offers and getting that message out- this is no David and Goliath and really not any underdogs either. You've got a market leader, a former market leader, and the most successful company in the world all with incredible financial resources to make sure the public knows exactly what they offer. Sony has no unique advantages over the other two. The Playstation may currently be synominous with "video game" but then again so was Nintendo once upon a time and it may be Xbox in the future.
On the software side of the house there will always be smaller titles that unjustly go unnoticed due to lack of advertising, etc (Psychonauts being perhaps the most recent example). This is not the case on the hardware side though. Each console manufacturer has only themself to blame for their success or failure.
I never said which console I liked more did I? I like my PS2 and I certainly didnt purchase it out of ignorance. I never said everyone does. Its just as someone else said, the PS2 is more of a household name, and this helps sell it. many people dont even look into the systems and decide which one they want. They dont make actual informed decisions, they simply purchase things. Its the society we live in more then anything else. They know the Xbox as the system with Halo, and the cube as the "kiddy" system, and the ps2 as the video game system. Does that mean you purchased it out of ignorance? No. Does it mean everyone who has one would have bought a different system had they looked into it? Of course not. Dont get your panties in a bunch here, nobody is starting a flame war about consoles (because really who cares), its just that sometimes the name playstation sells the system more then the actual merits of the system. While the merits are most definatly good for many people, it doesnt fit everyone. If you buy something simply for the name it holds, as would be the case many times for playstation (and many other products people purchase) I think it would be safe to say you made an ignorant purchase. Now you may have accidentally bought the best product for you, but you might not have made an informed decision. Dont take it personally when the society we live in buys things more for the name it carries then for the product itself. It happens in all areas not just video games, and everyone is guilty of it to some degree.
Please note as a disclaimer, not once in that post did I inuslt the ps2, xbox or gcn. They are all good little systems in this world and I hope I didnt personally insult someone by implying that one particular system may not be a fit for some consumers. Also note that I never made note of which system is my favorite, and most of all never tried to force my belief in which system is best for me upon another. I really hope this can move on without being a flame war and people can simply acknowledge that yes, sometimes we as consumers do not make the most informed decision when purchasing an item. End of disclaimer.
Edit: And just as a nitpick (and in all seriousness not aimed as a personal attack):
most successful company
^-- Micorsoft is not this. That honor would go to walmart.