Red --> Yellow --> Gold --> Silver --> Ruby --> Sapphire --> FireRed -- LeafGreen --> Emerald -->
Diamond --> Pearl --> HeartGold --> Platinum --> Black --> White --> White2 --> Y --> Omega Ruby.
Only games I have never played are Blue, Crystal, SoulSilver, X and Alpha Sapphire.
I know I played Gold/Silver/Sapphire/Emerald/FireRed multiple times as well.
Yellow had well over 100 hours. Gold was my main Gen 2 game and had well past 300 hours by the time I was done. Original Ruby was my biggest game ever, I took that all the way to 999 and beyond. Played Emerald a ton too, at least 200 hours but I can't remember exactly. Diamond was another 400. HeartGold was around 200. Y is at like 810 atm and will likely keep climbing. Already at 150 for Omega Ruby (although it should be much, MUCH more if we factored in SR's). All of the others would have been between 40 and 100 hours.
I have played a lot of Pokemon.
Wow, that's a ton of Pokemon!
I have played tons too though, especially in relation to the game-time for my other games.
On Omega Ruby, I currently have about 31 hours, with the number sure to reach at least a hundred.
On Y, I have about 120 hours, and it will keep climbing. I'm planning to do a nuzlocke on X also.
Diamond was the only game I played for an entire year after it came out, and I have about 300 hours in it (I didn't game much).
In FireRed, I had multiple play-throughs probably adding up to about 100-140 hours until the game stopped working.
In Platinum, about 60 hours.
Soul Silver, about 30 (I always hated gen 2).
Black was another 70-80 hours.
On Emerald, I'd add another 200 hours or so.
Before I got a GBA SP, there was this game on the computer called Pokemon Simulator (fake, I think), on which I probably spent about 40 hours.
Overall, I think Pokemon has made up more than 50% of my overall game time since I started playing.