Best & Easy way to secure WP sites?

Several of my sites were hacked (somehow my .htaccess file was affected, and was redirecting to .ru sites).
Although its no big deal to the site itself, i was able to fix it within minutes by replacing it with my 'clean' .htaccess file.

What's the best and easiest way to protect WP sites? I have read about plugins that help secure them, do they work well?
Whats your way of securing your sites? Thx