Looking for a desk lamp... ?Tizio  

Even after so many years...
Richard Sapper's Tizio stands alone and no one has been at that height ever since.
http://www.artemide.com

Check out YLighting
They have most of the currently available high-end, well designed lamps.
Right now, they're having a sale on the classic Tizio.
Assuming you're in the U.S....I don't know if they ship overseas.
Minneapolis, MN USA
http://www.ylighting.com/modern-classics.html

TIZIO.......is the answer!
your instict ot go for a tizio is right on. it unexpectedly works well with all aesthetics in my opinion. i have nerver had the urge to replace mine as it more than suits my lighting needs. they used to be much less expensive though.

Don't ignore the Herman Miller Leaf lamp, either
They're nice too
http://www.unicahome.com/p27045/herman-miller/leaf-light-by-yves-behar-f...

mario has a point. Also,...
mario has a point. Also, once you set your mind on something as unique as the Tizio, it may be hard to look elsewhere. The only thing to keep in mind is that Halogen lamps, while allowing for slimmer designs, get hotter than regular incandescent lamps and are more sensitive to surface contamination. Not sure about other pros and cons.
As for other suggestions, I like the functionality of the Jieldé Lyon lamps designed by Jean-Louis Domecq in the 1950s (see link). They were recently reissued along with a new smaller model (pic 1). They are known as very sturdy and flexible lamps.
Another favourite is the "Midgard Lenkleuchte 114" designed, or rather, developed by Curt Fischer in 1922 (pic 2). It inspired many later designs.
A different style of lamp that also works rather well as a desk lamp is the Kaiser Idell 6631 designed by Christian Dell in 1931 (pic 3).
I also like the Mouille inspired Weeks lamps, but I am not sure if there is a desk model.
Of course, if money is not an object, I would go for anything by Serge Mouille.
http://notonqueen.com/jielde.html

Tizio's are great - but...
Tizio's are great - but watch out for burn marks, loose arms, broken transformers etc if buying secondhand - later ones with the different bulb holder are much better. The Dove lamp (1985) by Marco Colombo for PAF is similar to the Tizio and maybe a bit less cliched - ironically for these you need to go for the early ones as they are better made!
A question about the Jielde lamps - I've had a number of these over the years (I bought one only yesterday in fact) but all the ones I've had, all bought fresh (ie unrestored), have been designed to be screwed directly to a table, but recently I keep seeing ones like the ones shown here with circular bases? Are dealers now adding the bases to make them more saleable as desklamps rather than as industrial lamps?

TIZIO :
a TRUE classic...get the standard size in black...it was 1972 or around then?

one of our closest...
one of our closest friends bought a Tizio when they lived in Switzerland last year, and have it in their home living room .
i have to be honest with my Design addict friends , It leaves you cold as Ice, now i know better than anyone that it is a classic and is the next icon, but it leaves you with a machine age feel, I personally feel there are so many other great lamps out on the market that will give you a better feel for your home living room or den, but for the desk in the office it is great,

another classic from artemide
I still love the Tolomeo from Artemide after 10 years of use.
The classic Anglepoise isn't bad eiher
http://www.anglepoise.com/shopdisplayproducts.asp?id=44&cat=Anglepoise+T...
http://www.tolomeo.be/Front/collection.asp?IDCollection=1

paulanna
Reissues are factory fitted with a base, as seen in the picture in my previous post.
Vintage lamps are usually retro fitted with a brake disc, as in the picture below.

Thanks Gustaf
A brake disc!...
Thanks Gustaf
A brake disc! Fantastic! And presuming one is using a recycled disc - green!

Classic Luxo
I'm a sucker for my luxo. It's both modern and classic at the same time. None of the pictures I can find seem to show the lovely little details and craftsmanship that set it apart from a 19$ drafting lamp.