Pikachu will always have a special spot in my heart, which is understandable as he's the mascot of the entire series. I do like Raichu, but he's never really been in my top favourite Pokémon. But for some reason, I have a soft spot for Pichu. Maybe it was because of that time that I found one, and I wanted to train it, and it was so weak that it was nearly impossible, but I pulled through. Or maybe it's how my friend once gave me one without realising it was shiny (which I didn't realise until afterwards either). Or maybe it's just that it's cute. Who knows? Bottom line, I'd say Pichu is my favourite, with Pikachu as a very close second, and then Raichu coming in third.