[X] My Assistant

[UmbreonEspeon1]

It is a mixture of both. I usually quickly go through the main story and then go back to catch the Pokemon I did not catch while I was going through it the first time. I like getting all my badges so I can take my time training Pokemon at any level.
The longest game play I have on any of my games is Soul Silver, because I was getting back into Pokemon at that time, and trained all my Pokemon from a lower level initially until I started trading with other gamers. I am playing Soul Silver, Heart Gold, Diamond, Pearl, Platinum, Black, White, Black 2, and White 2 all around the same time. Pokemon X and Y will be added soon too.
I finished the main story in Soul Silver, Black, and Black 2 at the moment.

[Meowstic]

Most of the games take me 30 hours; however, in White 2, it took me 50 hours. Not because it was difficult, just because I was having fun. I suspect I'll spend a lot of time in X, too, but who knows?

[Lars Neil]

If I get lucky [I seem to randomly either have a run where I'm never underlevelled and always overlevelled, or the other way around] I can beat it in a week tops. If not, maybe a month or so.

[pootergray]

On pokemon black 2 I finished in 17 Hours.

[Emmagurd]

It's always leisurely for me. I'm ashamed to admit that I haven't even "completed" some of the Pokémon games I own (Pokémon Black 2 being one of them).

But the ones I have "completed", I've not rushed to do, just took my time. I like it that way, means I get to train up all of my Pokémon in my own time, and really think of how to train them up.

[Wastelander]

Trying to think back...I'd say that the old GBA took me the bones of 10-15 hours, with the same applying to all the normal Pokémon games before B/W. Then I think White took me at least 20 hours do, with a guide at that. I haven't even completed Black 2 yet so yeah...

[Letan]

I play it a bit on the slow side, but is far as gameplay time goes it normally takes me anywhere between 20 - 40 hours to reach and defeat the Elite Four. In the early days I could do this in the span of a week or two, but now that I have work it'll probably take me at least 2-3 weeks to beat, if I'm lucky. Realistically, the pre-E4 stuff will keep me occupied through the end of October.

[Flamer]

Pretty leisurely to be honest. Had a couple of very quick run throughs on FireRed when I was doing restarts to get all the starters. Had to unlock the National dex each time to transfer them over to Emerald. But for a main playthrough I tend to take my time, especially with post Elite 4 stuff. Still don' think I've finished all 16 badges on SoulSilver yet...

[jayrachi]

A leisurely 50-60 hours.

[Yamper]

A leisurely 50-60 hours.

Round about this ^

I like to enjoy the game, level up things when I have time to do it, before I continue on in the story. I like to get my Pokémon to roughly the same level (usually a 2-3 gap between the highest and lowest).
I sped through my Pearl once and actually ended up missing quite a chunk because I was rushing things, so when i finally get my Pokémon Y at the end of the month I'll be sure to go through things slowly.

[xXJessicaPandaXx]

I don't really like rushing through games and tend to take my sweet time with them. I could probably finish the game quickly as everyone else, but since I like to take my time it takes me a whole lot longer. I like to explore everything I can so I tend to avoid progressing through the main story. I still haven't even completed pokemon x yet and I'm already at around 50 hours with it and still need to get two more badges. I just like to enjoy the games fully and take my time with them even if they take me more hours to complete them than they should.

[LeasCelyn]

My record for a first playthrough is three and half days for BW, it took me slightly longer to beat X and Y but still about four days. I only rush the first time I go through a game, my second playthroughs tend to be much more relaxed.