On every single playthrough I ever did of Yellow, I kept Pikachu just long enough to satisfy the happiness requirement to convince the NPC to give me Bulbasaur and then immediately boxed the useless thunder rat, never for it to see the light of day again.
On Black 2, I boxed Tepig as soon as I unlocked the ability to trade and brought in a Totodile that I bred in White 1 to serve as my starter. As for the Fire type slot on my Black 2 in-game team, Tepig was replaced by Growlithe, who in turn was eventually replaced by Chandelure once I got far enough to catch a Litwick.
Outside of the main handheld games, I don't think I ever kept the Espeon and Umbreon on my team throughout the whole game in any of my Colosseum playthroughs.
Other than those, I'm fairly certain that I've always kept my starter on my team at least through the entirety of the main story in every pokemon game. --- This is no time to be arguing about time! We don't have the time! # of people who know the movie and character that quote is from: 24
I remember in my first Sapphire run I ditched Swampert for Kyogre (just for ingame) mostly for type coverage. --- Best weapon combo in tf2: http://www.youtube.com/watch?v=7oUWPbS4450&feature=channel_video_title http://www.last.fm/user/iammax
First time I did it was in B/W. Tepig, Oshawott and Snivy were so easily replaced it wasn't funny.
I didn't replace Fennekin this time around (as I was trying to use only new pokemon), but I might replace it when I re-run the game (which I was planning on doing before the Torchic event ended, damn Pokebank - now I may have to resort to buying a used copy of Y). --- 3DS FC - 4511-1011-4738 Pokemon X - Friend Safari: Marowak, Phanpy, Gastrodon (Pink)
I've never really ditched them until the end game. I did sideline Serperior and Chikorita, but they were still on my team and used every now and then, though --- Many Bothans died to bring you this post.