My favourite pokemon game is pokemon emerald because I spent 100s upon 100s of hours playing it over and over when I was younger. I was captivated by the magical world of pokemon. 

I have recently stopped playing due to my brother playing the ds whilst peeing and then droped it into the toilet. bye bye ds..

I will probably buy a 3ds when pkmn 3ds comes out since I'm 15 have no job.. Im working on it!

yellow because pikachu follows you around. :P
That's awesome. And cause you could get charmander, bulbasaur, squirtle without having to trade. That was awesome!  It also made the pokemon look like the pokemon you see today (made it look like the anime) . (red and blue looked a bit more realistic imo)

Granted I haven't played Black/White Or the advance ones. Silver is really close for me.

Yellow for me too.. talking to pickachu made the journey less lonely and getting squirtle, bulbasaur and charmander was also awesome..

Yellow was my first but I dont really remember it that well. I was like 6 years old... I'd didnt even know you could use the pokemon in the storage pc so I was stuck with 6 pokemon wish i knew . probably because I was slamming the a button everytime text came up...

Pokemon GOLD is my favorite. BLUE is a close second.

Still haven't played Black/White, though.

the original is always the best so its blue for me, a fine game i put MANY hours into and never beat it when i was a kid

Gold/Silver are my favourite pokemon games (and Gen), but Black/White comes as very close second.

Heart Gold/Gold, because of the amount of content, particularly in terms of breeding, the day/night cycle, the geography of the region and the story, and still had the feeling of "What's around the corner? What comes next?" that really made Pokemon a great experience, which I felt lacked in the Sapphire/Diamond generations. I felt being able to play through Kanto after Johto was great, too. I will say I have been massively impressed by Black, and if I ever find the time to go through the post-story content, it may come in at a very close second.

Gold for the first 30 hours or so.

Platinum for post story stuff.

I haven't finished  Black yet, so I'll go with Gold/Silver/Crystal.  If the rest of Black continues as it is, it will probably be 1st.