Hmm....
Some Number Crunching
I am not sure if I have all names right - probably not - but you get the idea.
A +1 Holy Lawful(or Chaotic) Composite Mighty +5 Longbow of Flaming Burst, Frost Burst, Keen with +1 Arrows of Shocking Burst, Acid Burst, Sonic Burst.
Cost:
200.000 gp for the bow and 98.000 gp for 50 arrows.
Allows you to deal a damage of
1d8+5(from Strength)+5(from Arcana Archer Enhancement Bonus) +5d6 (various energy damage) +4d6 (various alignment based damage).
= 1d8+9d7+10
In case of a Critical, it would be 3d8+30+34d6.
Realistically, the damage would be lower, since most monsters that you have to attack with such a killer bow will be immune(resistant to some of the damage types.
I think, the more interesting thing is the flexibility. Since we all now that most enemies cannot be harmed with all types of energy, you could have a bigger sortiment of arrows, and you would probably consider to chose the bow enhancement bonus a little different.
(It might be a bit useless to combine both cold and fire effects - though many monsters are not resistant nor immune to both types of damage).
If I remeber correctly, the 3.5 Bane enhancement is only a +1 enhancement equivalent, so you could have a Bow with Dragon, Giant, Demon, Devil, Undead, Abberation, Drow and Ooze Bane. (But probably it would be more useful to only have appropriate arrows for this

)
Mustrum Ridcully