FFIX of course. Here are my reasons why.
FFX They just got to be TOO powerful. I killed the final boss in 2 hits using ONLY one summon. (and I NEVER got CLOSE to being fully maxed out with everything.)
FFVIII Relies on you to use your summons for just about EVERY battle up unti lthe last battle which took fricking forever without my summons.
FFVII Good use of summons but never got the chance to use them much.
FFVI NEVER used a summon through the whole game unless I got bored. All they ever did was waste MP and time as Ultima and such did the job faster and cheaper.
FFV by the end the summons were ok but still we weak against the final boss.
FFIV Good usage but still most summons were pointless (bomb? Sylph? Asura? what was the point?)
FFIII good because they had more thne just one kind of attack but bad as even the mighty Bahamut was only hitting for maybe 1000 on the last boss. Waste of MP for anything but cure4 with my sages in that battle.
The reason why I chose FFIX's summons was clear. They were strong and very usefull. I found EVERY summon usefull but 2 Atomos and Carbunkle. But I used them all the time as they were well worth the MP cost.
