A good one is,O&O Defrag. less the one hour to Defrag.  

I use Defraggler by Piriform (the CCleaner people) which is extremely quick.
It's still in Beta but I've had no problems at all.  

diskkeeper pro, defrags my 160Gb drive in 25 minutes, plus gives other options as well.

As well with a very interisting defrag option "On next boot" which is very fast ...

You'll probably need to find a site with some form of test/comparisons....

People here will be quoting times for differing drive sizes....differing defrag % and differing selected defrag options....

Think "apples and oranges"...

I currently use a free version of O&O Defrag. I like it, seems fast and it give options for defraging that I haven't seen in other programs.

Of course just about any of them will have some special features. Considering getting the paid version of O&O and also trying Defraggler.

Just an opinion, fast can be relative to the size of the HDD, defragmented files and available free space on the drive. I know I have read that somewhere, I'm not smart enough to know that by myself.   

Perfect Disk 2008 by Raxco is faster than all others for me.
10 mins 250Gb with 100Gb used
Licence is for 3 computers too but works across network too.
Defrags at boot your system files, pagefile and MFT.
Much cheaper than Diskeeper Pro which is also very good.
Ultimate Defrag 2008 by DiskTrix just out and gets good ratings too.

I tried several defraggers and came to the conclusion that PerfectDisk is the fastest. It's not very fast--it usually takes 4-5 hours for a complete defrag, so I tend to run it overnight, but I've left other defraggers going for upwards of 8-10 hours before.

I have mine set to auto defrag. I can't tell you how long it takes as it is constantly doing it's thing. It does not interfere with anything I am doing on the computer.

mstDefrag. It works in the background so I never have to defrag. You can't get any quicker than zero!

Considering most people derfrag overnight I don't see how it really matters.. Windows defrags my 300 Gig overnight with plenty of time to spare.

My Suggestion.. Sleep n' Defrag   

At 4 hours it would seem it had'nt been defragged in a while,even if you reformat install windows & get the updates it will require a fair bit of defragging ,regardless if you use a 3rd party software it will still use the windows defrag engine to achieve it's goal,me personally i defrag sometimes daily or whenever the mood takes me,if it's bad i'll let it run overnight in safemode & just use the original windows defrag to do it,if you setup a routine there's no need to spend money unless your downloading,installing & deleting (amongst other things) gawd knows how many programs in a day & it would be handy to degfrag on the fly etc,if you keep on top of it the defrag won't take long.

ps: before defragging make sure the hybernation option is unchecked & set pagefile to 0 (the two green strips in analyse is what the afore mentioned are & cannot be defragged) unless removed)then boot to safe mode & defrag, once defrag is complete reset pagefile to custom size & set it at one size in the min & max this will avoid unnecessary fragmentation

I've been using the free AusLogic defrag and I have 1 260gig with Object Desktop installed along with about 5 games and tons of other things and its never taken me longer than 30 minutes to go through a defrag. And that includes my 160gig hardrive which I use for additional backup.

So your saying the prog you use can defrag any amount of fragmentation in 30 mins pfffft me thinks a few minor details are missing sonny

Works for me so far....go figure!