Hello guys, longtime Wolverine fan here!
I know little to nothing about Deadpool, I watched the Wolverine origins movie, and it gave me some information.  
However people are at an uproar with the movie and its "inaccuracies".   
So as the title states, what Deadpool comic series should I buy? Which ones have the greatest stories and one liners? 
 
Thanks for your time, I won't be giving it back. :)

Anything Cable and deadpool,Suicide Kings

Pretty much every other Marvel book coming out every week has some kind of Deadpool appearance.
 
The best Deadpool stuff is Joe Kelly's run. I'm also enjoying the current Deadpool series. Check out Deadpool Classic vol. 1-3.

Thre Joe Kelly/ Ed McGuinness run.

I'd suggest startin' from the beginning. Try get your hands on the three Volumes that are out.  Avoid Cable & Deadpool for the moment and Suicide Kings.

Try Deadpool Games of Death 
If you will like it then Try Cable & Deadpool

Deadpool - The Circle Chase - Sins Of The Past, Deadpool Joe Kelly's run, Cable & Deadpool, Deadpool - Suicide Kings 

Jeez, I went to my local comic book store, prices were out of this world for the classics. And everywhere else, where the books were decently priced in-store, those locations were sold out. Guess we love Deadpool up here, must be since he is Canadian too. All in all, the Indigo online had good prices for the classics, circle chase and sins of the past are sold out everywhere, the other series are available, however, I just want to get to know the old Deadpool first. I pre-ordered the new X-FORCE volume 1 hardcover as well (covers comics 1-11 of the series) for $23. 
 
Thanks for the guidance people, I was getting lost with all the Deadpool spinoffs and reboots that were not very familiar to me. :)