Best attacking moveset

For quick move Thunder Shock is clear winner.
For charge move all 3 have their fans, I personally prefer Thunder. Thunderbolt seems more efficient though, more usage, less overkill, etc.
If you ask me as long as you dont get volt switch or discharge you are good

Thunderbolt is efficient, as it can be thrown more often. If you use Thunder, the defender will throw a charge move of 1 bar on you, which is really strong. It is really a big pain for your attacking Jolteon, possibly even faint.

Thunderbolt was the best even before the Gen2 update. After the update, Discharge edges out Thunder.

They are all about the same time, so Thunder obviously has the higher damage per second, but it also costs a lot of energy. Thunderbolt and Discharge are more energy efficient and can be used a lot more often.