I would suggest the Linksys WRT54GL. I had the Linksys WRT54GS and that thing was a turd. It constantly signed me off of the PSN, and would drop the connection on my computers several times a week for a minute or so. I got the WRT54GL though because it's based on Linux and you can flash it with 3rd party firmware, plus it's a 7 time winner of the Newegg customer choice awards for routers ;-). I bought it, immediately flashed it with the DD-WRT firmware, and I haven't had one single connection problem yet. It's been up for 122 days now without a single fault.
As stated before, unless your PS3 and/or computer(s) are far away from the router, you really don't need wireless N. Your internet connection is somewhere between 1.5mpbs - 10mbps. Wireless G runs at 54mbps which is more than capable for your online gaming. Unless you need to do large file transfers from within your LAN and need the speed, wireless N might be a little overkill.