I've seen LSWs twice, both times only briefly. Rare, small, and secretive. Hard to spot. Count yourself lucky if you ever do see one.
I'm yet to get a woodpecker picture that wasn't a tiny silhouette of a GSW.
Nightjars are brilliant, except when they wake you at 3am, or as in my case the first time you ever encounter them is at dusk when you are lost and they are calling and doing display flights (with the weird wing claps) just above your head and you can't see what on earth it is that is hurtling about making those unearthly noises. Scary.
For truly weird sounds though, the Manx Shearwater wins every time. Skomer island at night, at the right time of year. Thousands of the blasted things all gorbling and gargling away. Impossible to sleep, especially with the juveniles mis-judging landings and crashing into things, and big gulls trying to pick them off as well. Madness.