They're pretty much the same... But some Pokemon are only available in one of the versions, like Dialga in Diamond & Palkia in Pearl. Get Platinum if you can't decide, it has more features & you can find all the Pokemon from Diamond & Pearl in it (I think).
If you haven't played Diamond or Pearl, then get Platinum. Which is pretty much the both of them in one game.
oh yeah, i have play it using emulator No$GBA 2.4a... the gameplay it's so slow... and cannot play using 2.6a...
Diamond for Dialga. Pearl for Palkia+STRONGER POKEMON Dialga: Steel+(i forgot) type. Palkia:Water+Flying type
diamond! it's my birthstone! haha honestly i chose to play on diamond coz i like dialga better, it looks like a gigantic unicorn-dog
I would agree, Platinum would be the best choice. You can get most of the Pokemon from both versions. Just some minor setback is Glameow, Purugly, Stunky and Skuntank aren't available. You'll have to use the GTS (Global Trade Station, or how it is in Platinum, Global Trade Terminal) to get those Pokemon. Otherwise, the gameplay is awesome, there are new forms for three Pokemon. It's worthwhile. Just, you'll be missing the Shaymin event for Platinum... ._.
Take platinum couse there are some good extra's: 1. you get 5 minigames extra 2. You can choose between dialga and palkia at a certaind point 3. You can capture all pokemon of both games 4. it has a better multiplayer with an upgrade of the battle tower (and the Trade center) 5. you can save replays from your matches. but if you have to choose between Diamond and pearl pick Diamond. you can get a Skunktank (a skunk) instead of an Purugly (an oversised cat) and Dialga is cooler than Palkia.
