Keyspan USB 4-Port Serial Adapter (USA-49WLC) Serial Adapter

Pros: Simple to set up, very reliable.

Cons: Shape makes them slightly unstable when fully populated.

Review: We have several of these that we use as debugging serial ports for Windows boxes. They are lab beasts, so they get dropped on the floor, mistreated, and general banged around. They just keep working, no hiccups or glitches. They replaced a digiboard ...