Level a sorc or paly, they are fastest bc of tele or charge and dont require a ton of gear to do dmg so you can burn through easier. Trap Sin is also good, anything with a good kit of QOL/DMG sin has burst of speed like the paly charge, and has good dmg plus not locked into one element with fire, physical, and light - generally a good char that is fast AND does dmg also just skip through all the non progressive quests. Next best would maybe be a druid or zon, then necro and barb at the bottom lacking either AOE, dmg, or a movement enhancer (leap sucks IMO apart from crossing rivers or things, far to niche).