I'm so torn when it comes to Dawn.
I absolutely LOVE her character design, both in Diamond/Pearl and Platinum. For myself personally Dawn and May are tied as my favourite female player characters.
I like her in-game personality as well, when she is in the NPC role if you play as Lucas.
But I fucking despise her in the anime. I hate what they did to her. She's whiney, spoiled, irritating, her voice is grating and awful, HER FUCKING PIPLUP IS THE WORST GOD DAMN THING...
It just sucks. Outside of the anime she is pretty much my fav girl, but I abandoned watching the TV show in the DPPt/Sinnoh arc because she was such a crap character. And that's always bothered me. Like - god damn.