This is fairly outdated but I hope it helps.
Routers
The following routers have earned the Xbox Live Compatible logo.
Microsoft Supported Firmware Wireless Standards
MN-100 1.08, 1.11.017 Wired only
MN-500 1.08, 1.11.017 802.11b
MN-700 02.00.07.0331, 02.00.08.0333, 02.01.02.0590 802.11g/b
D-Link Supported Firmware Wireless Standards
DI-524 1.05, 3.00 802.11g/b
DI-604 2.18, 3.2, 3.36, 3.51 Wired only
DI-614+ 2.18, 3.2, 3.35, 3.43 802.11b
DI-624 2.25, 2.28, 2.42, 2.50, 2.70 802.11g/b
DI-634M 2.01 802.11g/b
DI-784 2.38, 2.42 802.11a/g/b
DGL-4100 1.2, 1.3, 1.6 Wired only
DGL-4300 1.2, 1.3, 1.6 802.11g/b
WBR-1310 1.01 802.11g/b
EBR-2310 1.00 Wired Only
Linksys Supported Firmware Wireless Standards
BEFSR41 (v3) 1.04.8, 1.05.00 Wired only
BEFW11S4 (v4) 1.45.3, 1.50.14 802.11b
WRT54G (v1, v2, v3) 3.01.3, 3.03.6 802.11g/b
WRT54GS (v2) 3.37.6 802.11g/b
WRT55AG (v2) 1.10, 1.79 802.11g/b/a
Netgear Supported Firmware Wireless Standards
WGU624 1.0.1.2EN, 1.0.1.9EN 802.11g/b
WGR614 (v1) 1.40 802.11g/b
WGR614 (v5) 1.0.7_1.0.6 802.11g/b
WGR614 (v6) 1.0.11_1.0.7 802.11g/b
WGR614 (v7) v1.0.12_1.0.12NA 802.11g/b
WGT624 (v2) 4.2.6_1.0.1 802.11g/b
WGT624 (v3) 1.0.12_1.0.1, V1.0.120_1.0.1, V1.0.128_1.0.1 802.11g/b
WGT634U 1.4.1.8, 1.4.1.10 802.11g/b
WPN824 1.0.10_1.0.7, V2.0.15_1.0.11 802.11g/b
ZyXEL Supported Firmware Wireless Standards
X-550 X-550_V1.1 802.11g/b
P-330W 1.8 802.11g/b
Incompatible Routers
These routers have been found to be incompatible with Xbox Live.
D-Link Linksys Netgear SMC
DI-754 BEFSR11 MR314 7004VBR
DI-764 BEFW11S4 (v2) RP114 7004WFW
NR041 RP334
RT311
RT314
Wireless Bridges
The following wireless bridges have earned the Xbox Live Compatible logo.
Microsoft Supported Firmware Wireless Standards
MN-740 1.0.2.21 and later 802.11g/b
Linksys Supported Firmware Wireless Standards
WGA54G 1.10 802.11g/b
WGA54AG 1.0 802.11a/g/b
WGA54G (v2) 1.6 802.11a/g/b
Gateways
The following gateways have earned the Xbox Live Compatible logo.
Model Supported Firmware Wireless Standards Logo-Certified With
Siemens/Efficient Networks Speedstream 6300 3.0.2 (004-E771-A3Z), 3.2.0 (004-E771-A5X) 802.11g/b Sympatico (Bell Canada)
Siemens/Efficient Networks Speedstream 6520 4.0.0c (004-E752-A4E config 003-w093-G0A), 4.2.0 (004-E752-ABS), 4.2.0b (004-E752-AEJ) 802.11g/b Sympatico (Bell Canada)
Netgear CG814WG 2.94d02 802.11g Comcast
Actiontec GT701R QW04-3.60.2.0.6.3-GT701 802.11g/b Qwest
Actiontec GT701WG QW04-3.60.2.0.6.3-GT701-WG 802.11g/b Qwest