Good Pokemon Team to go for Elite 4 - Diamond

[Kardan]

I don't know what my first team was because I've beat the Elite Four too many times

But from what I remember, my starter and Dialga were around 55, and I pratically just relied on them, all the others I used to revive/heal etc.

[Heart Break Kid]

on my ruby i defeated the elite four around 600 times !
on Pearl atm im on 144