The paid version of Malwarebytes works well for me.

There are a couple of other applications that you could consider.

Adblock Pro (freeware, available as an extension for most browsers) blocks ads, including irritating pop-ups.

The free version of CCleaner (CCleaner - The world's most popular PC cleaner & optimization tool - Piriform) does a good job of removing temporary/cached files. It is also good for deleting unwanted programs.

I run CCleaner every couple of weeks - it usually gets rid of 1-2 GB of temporary/cached files.

Note that it will remove passwords stored in those files so make sure that you know all of your passwords before running it.

Most trusted password-sensitive sites (like NT) allow you to select "Remember Me" or similar which means that logging on after running CCleaner is easy.