Picard: Mostly stays within Federation Space as a diplomat, occasionally participates in defense actions, fucked with by Q when he's bored

Kirk: Went into unknown space for exploration, few resupply runs, war with Klingons

Janeway: Teleported into hostile alien space with no hope of resupply, hostile aliens aren't even the most lethal, loses medical doctor early

Sisko (not shown): Literally commanding a military installation at the front lines of a warzone.

Archer: