use strict;
use warnings;

local $/ = "<br>";

while ( my $line =~ <DATA> ) {
   if ( $line =~ /Title:.*?<\/b>\n?(.*?)<br>/s ){
    my $saved_var = $1;
    print "$saved_var\n"
   }
}

__DATA__
a whole
lot of  worthless
stuff
<b>Title:
</b>
STRING_I_WANT<br>
more worthless
meaningless stuff
or sometimes
<b>Title:
</b>ANOTHER STRING_I_WANT<br>