Hard to say actually... I'll just do series that have more than three entries, and I will say that I count "playing" as being a few hours of the game and I won't count demos.

Final Fantasy - Barring FFXIV, I've played all the mainline numbered entries. When it comes to side games, Japanese exclusives, cell phone titles, or sequels is where I fall off the bandwagon. I've played many of them but I'm far from having played all of them and I don't have any interest to either.

Persona - Barring the Japanese only cell phone games and P4 Golden on the Vita, I've played and owned every entry released in the series. Much like Cim, I've bought P3/P4 several times just to give them to friends and family members who haven't played the series.

Metal Gear - Is much like FF, where I've played all the canonical titles except Revengence (can't bring myself to), but outside of Ghost Babel, Portable OPS+, VR Missions, Metal Gear AC!D and Metal Gear Rising Revengence, I've played everything else and despite my whining that Kojima should move on and let the series rest, I'm pretty sure Ground Zeroes and MGS5 are in my future because the man does good things with the series.

Street Fighter - Seriously, I used to be obsessed and while I haven't actually picked up the Super versions of SFIV, I have spent many a night getting my ass handed on them by friends. I used to love this franchise but it peaked for me with the Alpha Franchise.

Breath of Fire - Barring Japan exclusive side games and the ports, I've played all five Yes, NeoCracker, there are five entries and you need to get over your delusions entries and its one of the few franchises where I can honestly say I feel the series gets better with each new entry.