24" IPS monitors are normally 1920x1200..however, 120hz monitors are better for gaming if you got a good rig that can push like 80+ fps.
for 120hz (at decent price):
Asus VG236HE ($280)
Acer GD235HZbid ($330)
Planar SA2311W ($315)
Samsung S23A950/A750 ($450/$399)
S23A950/A750 (expensive) > VG236HE (great price; glossy) > SA2311W (very good; matted) > Acer GD235HZbid
for IPS (at decent price):
Asus PA238Q (IPS, $270)
Dell U2311H (IPS, $285)
HP zr24w (IPS, $320)
U2311 is probably best for gaming, but if you want 24" zr24w and 2410 are both great. Asus is also good.