Does anyone have any scripts or suggestions on a general purpose Unix/Linux monitoring tool?

There are several commands that you can put together to give you a certain level of monitoring.

However, most commands are Type-specific to each flavor of UNIX. It would help greatly if you could tell us a little about your OS.

Although I have some other Unix flavors that I would be looking at like, Solaris, HP-UX, & AIX.

What kind of monitoring do you want?
Network? Disk? Process queue?

You may even look into using SNMP for this.
Just be advised to use a recent version - there were hundreds of holes poked in various implementations of SNMP not too long ago.

I would have to say all of the above. I have never used SNMP before, do you know of any good SNMP utilities?

I like a tool called 'gkrellm'. Find it on freshmeat.net.
The built-in monitors include: Clock, CPU, Proc, Disk, Internet, Net, Memory, File System, Mail, APM, uptime. It is a designed with a modular structure allowing developers to create their own plugins to monitor other aspects of your system. There are several dozen different plugins already available. Requires GTK and runs on Linux, *BSD, and Solaris.