*chuckles* I'm in danger!

I think damage immunity is one of the goofiest things. Resistance is fine. But fully immune to non magical damage? Come on, cut the martials some slack, especially if you're stingy with magic weapons.
Something like a fire elemental being immune to fire damage is fine though.
- How're you supposed to sword a non-corporal entity?
  
  With determination!
  One of the greatest flaws of D&D is insisting that martial classes ought to be completely mundane human beings. Pick your flavor, mythical heroes or anime characters, you'll find plenty of ways someone can deal with untouchable enemies and overwhelming forces using sheer brawn or precise finesse.
  All that said, the most boring way to go about it is to just hit it because your sword has a number.
  
  Punch them. Your body won't interact with them, but your soul will.
  
  How's a non corporeal entity supposed to hurt me?
- In 3e, there were enemies that were immune to "any damage or effect from any creature whose level was lower than level 20"
- damage immunity is one of the goofiest things
  I go with Keith Baker's explanation that a non-magical sword will still cut a werewolf and maybe even cause it pain, but damage immunity means that it gets back up and keeps fighting. Maybe it immediately regenerates, or maybe it just ignores wounds that ought to have killed it. In other words, you can stab the werewolf through the heart and the sword will in fact pierce it and come out the other side, but the werewolf simply won't die (and remains just as capable of killing you as it was before you did that).
  This does imply that if you're strong enough to cleave the werewolf in two with one blow, it still dies - it can't reasonably regenerate half its body or keep fighting without legs. But at that point, you're either out of combat (bound werewolf, guillotine) or so much higher level than the werewolf's CR that it really doesn't matter.
  Anyway, if I were the DM, I would only make players face a werewolf without magical weapons if either they were meant to be running away or they did something really stupid. I would also allow them to deal damage to it in creative but non-magical ways. Maybe they can lure it into a trap prepared ahead of time or even just cut off its leg, grab that leg before the werewolf can plop it back on, and then play keep-away. (Can you run faster than a werewolf can run on three legs?)
  
  Goofy from a game design perspective, not from a lore perspective. It's just so unfair to tell a player there's no way they can hurt something when one of the ways they could've hurt it is with a magic weapon but you've refused to give them any.

Roll for seduction. It is the only way.
- I'm a lover, not a fighter. A level 20 lover.

When your team decided to be all damage dealers and nobody put a point into recon skills / spells
- Spell casters are the damage dealers, though. The martials are front liners, not damage dealers

When the monk can punch your soul
- I played in a campaign that included a Wizard/Dwemersmith, Psionic Monk that could manifest acid fists, and a Cleric of the God of Knowledge. Funnily enough the wizard and cleric were TN so they kept irritating the monk who was NG

Ah yes, those moments when the +1 sword really shines
- I think it would be fun to rule that any magic item, attuned or not, counts as a magic weapon for the purposes of attacks. Then cursed items are useful and there's a reason people keep them lying around, and you have an excuse to have all sorts of joke magic items that are really just used as improvised weapons.
  
  have all sorts of joke magic items that are really just used as improvised weapons.
  Wait, yeah, wouldn't hitting a Poltergeist over the head with an algemy jug or even a potion bottle work? As a magic, improvised weapon?