Personally, I just tried “Syslog Watcher” version 5.0.4 and it does a good job. I can start it by hitting “Start Server” then configured syslog clients to point at it. You can click on a message, then it will show up in the message view with every detail. Additionally you can hold Control and Mouse Wheel Down or Up to zoom in or out (just like in Notepad++)

Of course everyone is aware of Kiwi Syslog Server. I find Syslog Watcher more interesting, but that is just me.