In that case pretty much anything should do, provided it can handle the connections for gaming. Some routers (especially cheaper ones) don't close old connections for up to five days or so, which totally ruins your experience. LOL
When I was on ADSL (including a stint with ADSL24), I used to use a BT Voyager 2091 and later an AM200 modem wired to a Linksys WRT54GL with Tomato on it. Those things can handle thousands and thousands of connections, are rock solid and stable. Basically anything with a Broadcom chipset should see you right.
Actually, email me. My email is in Trust. You might have to set yours up to access mine (it was ages ago when I joined so I've forgotten lol).