DS games are more original says Pocket Gamer
Pocket Gamer painstakingly grabbed data off of Metacritic's website and analyzed each portable system's line up to see how much of the top 60 games on each system are "original." This subjective test revealed that the DS has an originality score of 47 percent, versus PSP's 15. Games like Nintendogs, Brain Age and Elite Beat Agents helped boost the DS's originality ratings through the roof. When breaking down genres, the DS has 28% of its games in the genre-breaking "other" category. The PSP only has 3% of its games there.
Although the PSP may not have as many original games, it still beats the DS in terms of number of highly rated games. The PSP has 37 games with an 80 average or above, while the DS only has 27 (and three of those games are called Nintendogs.)
