I'll add that for Windows, WireShark makes for a handy syslog viewer, ironically enough. I've tried several other syslog tools, and really, Kiwi is the best for syslog out there, but the "free" version is a bit nerfed. Others I ran into were either poorly programmed (crashing on minor issues -- logview4net), had a poor interface (Star SysLog Daemon Lite), or didn't even run (nxlog)
You can use WireShark's filter language to drill down on log data. It's overkill, but until someone writes a free syslog viewer/collector for Windows and makes it decent, this is one field that will be a hard one for most people.
Example:
# Display level 6 alerts from 192.168.5.90 in WireShark
syslog.level == 6 && ip.addr == 192.168.5.90