I don't know how much you care about qualifications, but most people will give advice on questions like this based on anecdotal experience, which the average user typically has very little of. Even a person who has owned several laptops can still only speak for the brands/models he/she has owned, and even then one of them may have been a one-in-a-million lemon from an otherwise good product line. I don't mean to discount anyone's opinion. That's what we are here for and what you asked for... I only want to make you aware that some opinions might have cause to carry extra weight. I have been working on computers of nearly every flavor for nearly 15 years, about 10 of which have been doing it professionally. I have repaired more laptops than most people have even laid eyes on. Enough bragging; I hope you trust that I know my stuff and will value my input.
Besides the really good practice of dry-running the machine in the store with SEVERAL live CD's, you can also learn a lot by going to EmperorLinux
. Even if you don't buy from them, you can see what models/configurations they sell. They even give a rundown of features on each model they sell and describe its Linux compatability, item-by-item. It will save you a lot of time over digging through HCL's.
I can't recommend IBM/Lenovo enough. If durability is an issue, don't accept anything less than a Thinkpad. The same goes for compatability and support. I don't understand the comment above that Lenovo is shunning Linux. They have done a fine job of following in IBM's footsteps and embracing open source. They even have this page
on the Thinkpad web site touting the T60p's Linux compatability (they still won't sell it with Linux pre-loaded, tho. Gotta pay for that Windows licence and add Linux yourself). I have always used Thinkpads for my personal laptops and had excellent results. I started out with a 600E and battled my way through its infamous sound issue, and that is the ONLY major problem I have ever had with Linux on a Thinkpad. BEWARE: The old i-series Thinkpads are only Thinkpad by name! They are actually Acer whitebooks that are licenced to use the Thinkpad name. They will run Linux, but will take more work to get running right and aren't as well supported by the Thinkpad web site. Performance on them is also a joke compared to a comparably equipped true-blue Thinkpad.
I reiterate: I don't want to discount anyone else's opinion! That said; DON'T BUY A WHITEBOOK/HOUSE BRAND!!!!! Repair parts are practically nonexistent, warranty service is universally poor, upgradeability is spotty, and when the battery inevitably gives out, a replacement WILL NOT EXIST. If price is your one and only deciding factor, this will be your winner, but you will regret it in the long run.
Dells are kind of touch-and-go. Durability is not so great. Compatability is usually pretty good with some effort. Performance is average. Upgradeability is usually good. Repair parts are easy to get. Warranty is easy to get. Price:performance ratio is hard to beat. If price is more important than durability and you don't mind a little extra effort to get it going, Dell would do fine.
Sony is awesome, but expensive. You will pay about the same as you would for a Thinkpad, but they are not as durable and usually won't support Linux quite as well.
HP is a good compromise between performance, durability, and price. They are pretty flimsy compared to Sony or IBM/Lenovo, but they are tougher than Dell and Toshitba (er, I mean Toshiba). Performance, warranty, and support are all pretty good. Upgradeability depends heavily on the model. You will pay more if you want to be able to upgrade later. Linux support is about the same as a Dell or Sony.
Compaq will net you about the same as HP but will cost less. Upgradeability usually isn't as good. Higher-end Compaqs = Mid-range HP's...
Toshiba is the Fiat of the laptop world. I won't waste space saying anything more than *DON'T*...
Panasonic, Acer, Gateway, Fujitsu, NEC, Digital, Samsung, eMachines, AST: better than Toshitba but still not worth the headache. Most of them break as easily as paper mache, upgradeability is spotty on a good day, parts are hard to come by, and Linux support is more hassle than anyone but a masochist should deal with.
Also, a customized BIOS should not cause you much trouble as long as it is current and supports world standards like ACPI, etc. Nearly all laptops have customized BIOS's (unlike desktops) and you will really beat your head against the wall trying to get around that.
While shopping: Stay away from wireless chipsets that are software controlled (especially Broadcom) unless you don't mind battling with ndiswrapper and using someone's crappy ndis driver. The only exception to this is Atheros. They are software controlled, but madwifi works incredibly well.
Point to consider: I had a Thinkpad handed to me once that had been fished from the bottom of the murky waters of Lake Conroe. Repairs were minimal and it was good as new. I don't know of any other brand that can say that.
P.S. - Do a search on LQ for this topic. It has been discussed/debated ad nauseum in the past to the point that a lot of people who probably have a lot to contribute aren't going to reply to this thread because they have already said their piece on the matter a hundred times before.