I bought my Galaxy Nexus unlocked here and I love it:
http://www.amazon.com/gp/product/B005ZEF01A/ref=as_li_ss_tl?ie=UTF8&tag=acomprar-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B005ZEF01A
Pros:
1. Incredibly sexy: thin but not too thin, slightly contoured, more rigid than other Samsung Android devices thanks to the internal metal frame
2. Large, bright, detailed screen. However it doesn't come off as huge due to minimal bezel and the use of the bottom portion of the screen for contextual soft-keys. The screen uses a pentile-matrix configuration, but the pixel density is so good that you really can't notice unless you look very closely and even then it's difficult to tell. The blacks melt into to the bezel beautifully and the colors pop.
3. You get the very latest version of Android, with instant updates from Google. I have grown to despise carrier/OEM UI skins and their accompanying OS update delays. The Android 4.0 UI is a huge upgrade and behaves much much better, making such carrier/OEM skins even less desirable. The interface seems to have been reworked from the ground up for smooth, responsive operation. Transitions are slick, and apps run great. I haven't had app compatibility issues some others have mentioned; some games haven't been updated for 4.0 yet but most apps I use work fine. The whole experience is leaps and bounds over any prior version of Android. 4.0 seems made for this phone and works perfectly.
4. If you get the unlocked GSM version, it works on any GSM network in the world with up to 21mbps HSPA+ speeds. I bought it overseas and popped in a $30/mo T-Mobile SIM and it works perfectly, I get speeds between 3-8mbps in the SF Bay Area, with seamless transitions between EDGE, HSPA/HSPA+. Not to mention no carrier bloatware!
5. Everything in the OS works great: Wifi hotspot, bluetooth tethering, bluetooth HID (I tried Apple wireless keyboard and trackpad), battery and bandwidth monitoring, music controls on earphones, built-in equalizer, HDMI out over MHL. I am amazed at the relative lack of bugs in the OS given how new it is.
6. The device is relatively easy to take apart (according to iFixit.com) and OEM parts are popping up on ebay, so if you break something or something stops working, you can fix it relatively easily and cheaply (except the screen, don't break that! You would have to replace the whole screen/digitizer/housing assembly)
7. Thanks to having a single worldwide GSM model, there are plenty of compatible accessories available already
8. Touch sensitivity on the screen is great. The UI 'sticks' to your finger much closer than other Android devices I've used, though still not *quite* as close as iPhone -- however the iPhone people who have used my phone don't seem to notice. In fact, this is the first Android device I've had where iPhone people don't immediately fault-find when they use it, and seem kind of thoughtful and chagrined instead
9. Battery life seems pretty good for an Android device. Not as good as an iPhone, but I can easily make it through a whole day of moderate-to-heavy use. The removable battery means you can improve the battery life with an extended battery and can replace it when it starts to give out. The OEM extended battery provides a modest boost in battery life and fits the phone's shape very nicely -- I highly recommend this upgrade unless you really like the phone's recessed back.