SEUS PTGI in my opinion is the best, people are always talking about how it's buggy and stuff, but PTGI is still demo, and there are several other versions such as "SEUS Renewed" Which are bug free, and even SEUS PTGI has little to no bugs. I use SEUS PTGI HRR 2.1 which reduces frame loss. It's completely free and linked here: https://www.patreon.com/sonicether