More important than the manufacturer is the use you are putting it to, and the specification needed for that use.
There is a very good report in the latest Which? (April2012) on all-in-one PCs and larger laptops. (The three top laptops were one Samsung and two Acers, btw.)
Asus here - very few moving parts, durable as designed for engineers, built with big keys and, to date (15 months) proven very reliable. Price £550 fully loaded.
Fast is a relative thing. Any laptop you buy today will probably be 10 times faster than one 10 years ago.
Depending on what you are doing with the laptop you may not need it fast. If all you are doing is internet, email and office type work then none of that needs a "fast" laptop.
You only need a fast laptop for gaming, video editing and that sort of thing.
A fast broadband connection is probably more important.
You can get a laptop for £300 to £400 that will be perfectly adequate for most normal office type work, and with laptops lasting only 3 years or so (due to dropping them, breaking down etc) it is not really worth spending £800.
You may as well spend between £300 and £400 and buy another in 3 years.
I went to John Lewis last week - told the guy I wanted to spend about £700, then told him what it was going to be used for, & walked out with one costing £450 - the HP Pavilion G6-1362. I3 2.2gHz processor, 6gB RAM, 500gB hard drive.
My Acer (now two and a half years old and no problems) came from John Lewis, as well. Very good advice, two years warranty included , good price- an excellent place to purchase.
Thankyou Zacs-Master,DTcrosswordfan,VHG,sfby,Gingejbee & Gavmacp,you have all given me something to think about,especially Zacs-Master about the Hard drive, does a large Hard Drive on the laptop slow the laptop speed down???