HDPE ---> you will only find PEX ( PEX is crosslinked HDPE )
PEX ---> see above
PEX-AL-PEX ---> best choice, multilayer PEX / Aluminium core / PEX
PVC of any sch and size ---> loses plastifier and gets brittle, dangerous !!
Sch 80 CPVC 3/4" ( never heared... )
ABS ---> most dangerous, no UV...