For those days when you're feeling up to a good npc scrap-fest, I might recommend a Corsair or Outcast fighter. If you stick with missions below the 1,000,000 mark, you normally don't have to worry about enemy capital ship npcs. I usually prefer the eliminate, capture or base destruction missions, as they are usually a lot quicker. If you go for base destruction, be sure you read the mission text. Some missions require you merely destroy the base, while others require you to destroy the base and ships. Base destruction w/o needing to kill all ships usually allows you to get away with taking missions that offer more than 1,000,000, if you can dodge all of the fire.
I say Outcast or Corsair, as they offer decent amounts of credits in addition to the missions being in their home system, and flight distances are usually never more than 40k. Not to mention, there is a good player base for Outcasts/Corsairs if you want to team up with others for pve missions.
