Android SDK: Development reference device to test

Note: There were similar questions about this topic but were old threads. Also please note that this question is a development related question but not a personal mobie phone advice

I will start android development so planning to buy an android mobile device only to test my apps and work on it. I saw that at the moment there mainly HTC, Motorola, Samsung and SonyErricson android supported devices on the market.

Which of these brands do you think I should have as a development device? Or as a reference device? for example maybe the current Android emulators are close to HTC phones and a Samsung should be nice to test because it is different in screen size or by some SDK's? or it does't really matter cause other than the screen sizes I will always get the same results.

note: I live in europe

Get a Nexus S or it's upcoming successor the Nexus Prime (or whatever it's going to be called). They're easily unlocked for root access and are the purest breed of Android, without any of the vendor modifications like HTC Sense or Samsung Touch Wiz.

If you're seriously into testing, you won't get around to having multiple devices, preferably at least one model for each major vendor (mainly HTC, Samsung); might also get a tablet. Many of the obvious compatibility problems can be found using the emulator, though -- so do test in there a lot.

My opinion you can choose whatever you want. More "professional" probably is "Nexus One" from Google. I personally use HTC Wildfire S a and I'm missing it for all purposes. What screen size, version of Android or brand theme style - SDK support all sizes of screen (you personally can change it), Samsung, Sony Ericsson, LG and other companies has release add-on that user can use the native brand interface.

By the way first 3 monthes I've developed only using an emulator without device.