I'm a firearms fan, but UK laws prevent from buying anything real.
To that end, all my Armalites are replicas, but they're damn good replicas
you can't tell the difference (except they fire airsoft rounds, rather that 5.56)
In order on the wall, top to bottom: original AR15-alike, M15A4, M16A2, M4A1, M16A3-SPR with KAC free-float RAS.
Close-up of the markings on the AR15:
And of the M15: