As you probably know from seeing me on the LS1 boards, I think the M1-206 Mobil 1 filter is the best out there now that the UPF58 is no longer in production. The Bosch Premium is also a good filter too (not sure what part number for the long LS1 filter though)
The Purolator filters are very good but on the LS1 I worry that the L20123 might be too long, I think it's longer than the PF58. And I don't think the PureONE is good for any high performance application, especially not one with a small oil filter like the LS1 (even the long LS1 filter is still a lot smaller than most V8 engine's filters)