Im not a gamer and never was. On the other hand i would prefer cat cable. I just ran two (100 ft lengths of cat 6) in the basement.). wireless for me is outside. If you can run cat then why wouldn't you. lot faster and big diff.
If the run is easy at least. Even the basement was a bit of job. not impossible.
its done.
This is a common misconception. Wireless G's 54mb/s (and N's 300 mb/s) is significantly faster than any internet providers download/upload speed. (Unless maybe you live in japan or something).
The problem with gaming on wireless is how most routers use burst switching. That is, the router will obtain an amount of packets from the ISP and then send the packets to the wireless device as a bunch, or bundle so to speak. Rather than sending each individual packet instantly as soon as the router receives it, which is how wired systems work.
Good news though, Most routers (and cards) can disable this option. Example,
how to for Intel based cards.
Also, if you're running windows, I've heard disabling the windows zero config service can really fix some lag issues if you're having them.
Though, there is still going to be interference with wireless gaming (you never know when your mom will turn on that microwave and then your connection drops). So if you can, 100foot of cat5e is only 10$, certainly worth looking into.
TL;DR: There are options to try before dropping a wired line.