How do I download from SourceForge with wget?

wget follows redirects automatically. Just give the URL as an argument

wget 'http://downloads.sourceforge.net/project/romfs/genromfs/0.5.2/genromfs-0.5.2.tar.gz'

Start the download in chrome browser. When it starts cancel it and go to downloads page. You can see the url for the download. Copy it and use it with wget.

Click the link, you'll get redirected, and you'll see something like "Redirecting... if you are not automatically redirected, click the direct link.

Copy that [direct] link's location, paste it in the command-line like this

wget "http://downloads.sourceforge.net/project/lame/lame/3.99/lame-3.99.5.tar.gz"

That's it! It worked for me.

Edit: You should omit everything after the '?' character in the url, or else the filename will also have this part.