Hikvision is a big name in the IP camera industry, offering a wide range of cameras that cover the whole spectrum from small home-use cameras to professional high-resolution industrial models.
The DS-2CD2432F-IW is an inexpensive ($130) compact camera suitable for indoor use, with an impressive feature set. The 3 MP sensor offers higher resolution than many competing products from other manufacturers (Hikvision themselves also produce a DS-2CD2412F-IW model with a lower 1.2 MP resolution, but the price difference is not large, so we we would recommend going for this 3 MP model). It has both WiFi and Ethernet connectivity, and can be powered either by PoE (Power-over-Ethernet) or by a 12v power adapter, making it easy to install in any network environment. The sensitivity of 0.07 Lux, combined with built-in infrared (IR) illumination, allows it to function well in low-light situations, and it has a built-in microphone and speaker for two-way audio.