Played 'em all (except artificer), loved 'em all.
Level 1 Monk - d8+d4+6 damager per round (assuming 16 dex). So damage should not be an issue - they're on par with heavy hitting fighters and two handed wielders. They can do stealth for scouting. I'm not sure why you would not like them.
Level 1 Warlock - You are not doing the higher damage with Eldritch Blast, yet, you get a reasonable amount of damage (flat d10) from range and you get some spellcasting, plus a special ability based upon your patron. Plus, you have awesome built in story at first level due to your pact.
Level 1 Ranger - Compare to a first level fighter. What are you missing? A little self healing, a fighting style and heavy armor (which you often can't afford)? Even if you get no real use of Favored Enemy and Natural Explorer, you get an extra skill over a fighter and a better selection of skills, too. While generally weaker than a fighter at level 1, it is not by that much. And, given that they make great scouts, they have opportunities to do a lot of things fighters can't.