while (<DATA>) {
    print "$1\n" if m/gif"><\/td><td>(?:<b>)?([A-Z0-9\(\)\[\]]+)(?:<\/
+b>)?<\/td>(?:<td>(?:<b>)?([A-Z0-9\(\)\[\]]+)(?:<\/b>)?<\/td>)?<\/tr>/
+;
}

__DATA__
gif"></td><td>XXX</td></tr>
gif"></td><td><b>XXX</td></tr>
gif"></td><td><b>XXX</b></td></tr>
gif"></td><td><b>XXX</td><td><b>YYY</td></tr>
[download]

This should do what you want, and it takes care of all the <b> and </b> cases. Don't ask me to explain it, though.