Follow the link below to get all episodes and movies of naruto.
in the very last episode of the original naruto and he comes back on the first episode of Naruto shippuden
The very first episode of Naruto, episode 1.
The very first of Naruto Shippuden XD
the very last naruto shippuden episode will be episode 300 (the last episode)
Naruto summons Gamabunta at the very end of Naruto episode 56, but they introduce themselves to each other in episode 57
that's episode 51 watch it here http://narutovideoseries.com/naruto-shippuuden-51-reunion/
And Sakura slaps them? xD That's actually Shippuden Movie 3. ^_^
on the very first episode of shippudden
It is Naruto 168 here's the link: http://www.tailedfox.com/page-naruto-episode-168 TailedFox is a very good site to watch Naruto and Naruto Shippuden episodes.
www.animefreak.tv You can find animes from A-Z and it's very likely that you'll find any anime you want
naruto: ep 33 (very brief), 50 (very brief), 113 and a few fillers which i cnt find shippuden: ep 34, 83, 84 (all very brief)
It hasnt happaned yet :)