2 Low Intensity builds I recommend
Power Rifle Mechanist - Most brain-dead spec imo. Super tanky pet. Ranged. Set the pet's F1-F3 to autocast so you'll never have to touch it. All signets on utility skill slots. All you need to do is press 1-5. Berserker prefix. You'll probably do more DPS than most players in pug instanced PvE.
Condi Staff/Staff Mirage - You're invulnerable like half the time. 95% of the time all you do is dodge followed by auto attack. Celestial or Trailblazer prefix ensure you'll never die. Possibly the best open world solo build in the games. Can Solo everything in open world. Useful in fractals and strikes because you'll give perma alacrity and 25 might.
If you want something less braindead but on the middle ground between all specs, you have...
Power Quickness Scrapper - Not low intensity since you got more buttons to press. It's a bruiser so it has a lot of sustain through innate barrier generation and good damage. Perma superspeed to zoom around everywhere in combat and perma quickness for group settings. Easy to play but not as easy as the previous two mentioned. Half Berserker and Half Diviner prefix.