The biggest problem with the idea of serving under Kirk's command was the crew looked too dated to relate to. The 60's haircuts and hairstyles, the phrases they used.
Picard and crew came off as snobby to outsiders and lower ranked crew members.
The thing with Picard was, his command was relatively safe. Hell, they were exploring archaeological ruins during the Dominion war.
If you want a somewhat quiet career, I'd choose Picard.
Sisko--DS9 was more fun and exciting, but his situation was too damned dangerous. Maquis, terrorists groups, Klingons, Dominion. Some of those Pre-Dominion war episodes were downright nerve tingling.
If you want adventure and are a thrill junky, I'd choose Sisko.
Janeway was an nice compromise between the two, but... there was something about Voyager's crew that didn't click with me.
If you want to waste seven years of your life and get lost in the crowd with no promotion, I'd go with Janeway.
Ultimately I'd go with Picard. Cool uniforms, chances of promotion, holodecks, replicators and probably the most safe situation.