I have had the same Dell 21″ CRT monitor for over 20 years but recently it the image has started flickering and I have started to worry that it might fail or even catch fire.
The internet suggests that the ergonomically ideal screen size is 17″ because it matches your natural field of view. As you go larger gain the opportunity to display more content but it become more difficult to manage. The sweet spot seems to be at about 24″. The best rated monitor at this size is the Dell U2412M which has a 16:10 aspect ratio (better than 16:9). Dell have just released its successor and I could purchase this top rated monitor for only £ 180.
The monitor screen is beautiful. I have connected it to my HP Stream 13 laptop (a £ 200 ultralight!) and it works perfectly. The driver and software disk in the box was scratched but eventually I mananged to copy off the drivers and software.
Drivers installed OK and updated and Windows Update confirms that the most recent ones are now installed.
The Powernap software allows the PC to put the monitor to sleep when the PC sleeps. It claims that it detects screen rotation but this does not work for me.
The monitor comes with a good tilt and swivel stand that allows the monitor to be used in portrait orientation. It is unlikely that you would ever want to do this because in landscape mode the monitor is slightly larger than two sheets of A4 paper. The HP Stream 13 uses onboard Intel graphics and Control Panel > Display > Screen Resolution > Advanced > Intel HD Graphics Control Panel has the Rotation option greyed out so I think that is probably why the option is not appearing anywhere.
The Dell site has an excellent Drivers and Downloads section for this monitor and it suggests that Dell Display Manager can be used with this monitor and indeed it is listed as a supported device by that application. This application allows the user to make the same adjustments that are allowed by the buttons on the monitor. However it could not see the monitor and others have reported the same issue in the Dell forums and therefore I uninstalled it.
I note that this is probably one of the last Dell monitors to have a VGA input which is great for older PCs and laptops. It does not have a HDMI input but since it has DVI and this is identical to HDMI (but without audio) this is not a problem since you can purchase an inexpensive adaptor cable that works fine.
— update 2015-07-26 —
My VGA laptop died and I am considering getting a Microsoft Surface which has a mini-display port connector and no ethernet socket and only a single USB 3.0 port. To connect the Surface to a wired network you need to use a USB to ethernet adaptor. It is rather annoying that my Dell U2412M only has USB 2.0 which is slower and fewer interface types. If I had known that my VGA laptop was going to die I would have bought USB 3.0 U2415 for a few pounds more.