Favorite new evolution/pre-evolution introduced in 4th Gen?

Generation 4 brought us many new evolved forms of older Pokemon, meaning those that evolve from Pokemon introduced previous generations. Generation 4 also introduced two new methods of evolution: leveling up while holding an item and leveling up in certain areas.

It also introduced new evolution items such as the Dawn Stone, Dusk Stone, Shiny Stone, Oval Stone, Razor Claw, Razor Fang, Dubious Disc, Electirizer, Magmarizer and Reaper Cloth. There were also new pre-evolved forms of older Pokemon, such as Budew and Happiny.

What were your faves? Discuss!