Ah, sorry DaComboMan, presumed you were referring to the downloads, although there is a way NOT to receive email alerts for every topic you're subscribed to, here's how:
If you want to 'Watch' a topic and have that topic listed in your Control Panel but NOT receive email alerts for replies hit the "Watch Topic" button.
On the next screen, you have the choice of how to receive notification of changes, or in this case you would just choose "No Notification" and then hit the "Proceed" button.
When you start a new topic, you can choose not to receive email alerts for replies if you untick the "Enable email notification of replies?" tick-box found under the "Options" area near the bottom when making your new post. If you reply to a post, you'll automatically be subscribed to the topic but you can change how you want to receive notifications of replies, or whether you simply don't want notifications. You would do this by going into "My Settings" at the very top, right-hand side of the site, then choose the "Forums" tab and then the "Manage Watched Topics" link. Look for the topic you want to change your notification options for, and place a tick in it's tick-box.
Then finally, scrolling down to the bottom of the page you'll see a drop-down box with the available choices in it. Choose "Change To: No Notification" and then hit the "with selected" button and you won't receive email alerts again for that topic.
If, when replying to posts you simply do not want to receive any notification and don't want to be subscribed then instead of using the "Fast Reply" box at the bottom of the post, you could use the "Add Reply" button which will take you to another screen to enter your text but underneath the "Options" area you can expand where it says "Click to configure post options" and in there you can untick the "Enable email notification of replies?". I know it all sounds a bit long winded, but if you do this a couple of times it becomes second nature
Hope that all helps

Cheers
Marko