Depends on your orientation from the router which is best.
PCI-E card is better becaue it is has a bigger antenna and not restricted to the 5v power and 480 mbps speed bus of USB 2.0
However if the back of your PC is facing away from the router then your PC is now blocking the signal and everything you gained with that PCI-E card is now lost.
The best PCI-E cards are the ones with antennas on a base station that sit on yoru desk but are much more expensive.
With all of that said, WiFi should be last option anyways.
If you just can not run an ethernet cable to your location then a powerline ethernet adater is better than wifi. Real world speed will be better, in most cases reliability is better, and latency is significantly better which is most important for gaming or live video/music.
https://www.amazon.com/dp/B06WP2ZT5N