I got to say Alexander, Palidor and Fenrir is the best but by the way don't you think Stray looks alot like Caith Sith (Final Fantasy 7)?

IIRC I read somewhere that in the Japanese version of FFVI Stray was named Cait Sith.

Espers were always far to weak near the end, but I often used Ragnarok and Seraphim..

Well probably Crusader (It might hurt my party, but it will most probably kill them) and Bahamut fantastic Esper.

Palidor and Crusader was always usefull for me. I would do Palidor to avoid boss attack and crusader as a suicide attempt ^_^
Like all others Espers do, Bahamut lakes powers... which stopped me from using him x_x

I valued the Espers more for the magic they taught me than any of their summoning skills. I almost never used them for that. In fact, I don't really use the summoning magic most of the time when I play FF games. I guess I just think it takes too long when most of the stuff they do can usually be accomplished by magic or attacks. (As a general rule)

i don't have all the Espers.. and i forget a few of them but Palador is really useful!! Ragnarok is also good.. depending.. but i don't summon much... Ultima! hehe......

Actually, I was never a big esper user during FF6. Most of your own attacks, physical and magical were so much stronger then them, I didn't waste my time. They come in handy during the tower of fanatics though. :)

I also dont use them to much but if i were going to i think i would have to say Ragnarok would be the most usefull outta all of them but really i dont use them to much

I mostly use raiden because he ownz :)

I love him, and I love odin too, but raiden is much worth it.