Daemon tools installs a rootkit. You may want it's functionaliy, and I do, but you should be aware that every file access will be examined by this rootkit and allowed to either pass on to the normal file system or not, at the discretion of the rootkit. That's how they hide themselves from anti-piracy measures.
Defraggler - also from Piriform, same as CrapCleaner is an excelent defragger with a catchy name to boot.
IrfanView - I agree with Killerclick, it's a MUST have.