Always been a Rocket fan. They were my favourites for years! <3
I love all the girls. I can't stand pitting them against one another. They all have their own strengths and weaknesses. Haruka/May and Dawn/Hikari might get a slight edge over poor Kasumi/Misty, if only because they had more focus during the series, as opposed to Kasumi, who mostly got her development (past the earlier episodes) in the hoso specials!
Kasumi had a funner personality, though, because I really love tomboyish girls. Hikari/Dawn was girly, bubbly, and clever, though, so she was undoubtedly fun, but Haruka/May was more like me in that she was naive and clumsy (well, in the beginning)... and a BIG eater. xD
Iris is a LOT of fun too! She's more like the tomboyish Kasumi, so I love that, and how agile she is~! And I'm biased in favour of dragons, so~ <3333
She's so adorable and funny too. I love how she butts heads with Dent/Cilan.
As for the guys, Dent is the funniest protagonist. All this "_____ time!" and tasting things and his vocabulary and fabulousness...! xDD
Shinji/Paul was my favourite rival. Just so epic. I loved how different he was compared to Satoshi. His brother's always a very interesting contrast.
As for less common characters, Shirona/Cynthia, without a doubt! ^_^ She's so awesome and confident... and inspiring! I love how gentle and adorably bubbly and easily confused (always cool and composed in battle! Outside of battle, what are decision-making skills, really?) she can be too. She's so powerful and amusing.