Yeah, I have kinda big collection of different manga, but nowadays I collect only Toradora! and HUNTERxHUNTER. The longest series I have complete is Yuugi Ou! (38 vols in Finnish and 22 in French).
Cool! The longest series I have complete is Dragon Ball Z (26 volumes). I only need one more volume (vol. 19) to complete Shaman King (32 volumes).
How many volumes do you have? I have 267 (I also count Weekly Shonen Jump as volumes).