Server Help

[BDwinsAlt]

I've been messing around with Ubuntu a lot lately. I really want a nice firewall to go on it. I've messed with a bunch of them, but a lot of them are complex and can only do so much. I'm looking for a firewall similar to zonealarm. I want to be able to add custom ports, not really IPs. What do you recommend?

Edit:
Never mind, after playing with Firestarter more I found that option.
You can still recommend some firewalls though.

[Solo Ace]

Just "go with the flow" and use iptables already, sick GUI bastard.