What is your budget?
I prefer 1200 over 1080 for monitor display. This is a personal choice though and mainly because web pages are shown a bit fuller and windows itself in general is displayed better than @ 1080
It really does depend how much you want to spend but I had regrets after buying a 24" instead of a 27"
24" may well be large enough for you but 26" or 27" is a really nice size for a monitor that is for multi media use. (30" becomes too large sat at usual desk distance for me and too small text with 30" @ 2560x1600, 27" @ 2560x1440 seems to be the sweet spot.)
If your budget is sufficiant and you go for a 26/27 inch then you should also be looking at monitors with a res of 2560x1440 and not just up to 1200 (Dell, Hazro, HP all should be looked at for their 27" monitors.)
If you are looking at spending just a couple of hundred pound then go for a better quality 24" over a cheaper 26"/27"
My personal advice would be that if you really want a nice 27" monitor but are struggling to get a good 1 within budget look out for the Hazro 27" monitors that are due to be released soon and will be released in glossy and matte screens and going by the their great price/performance of their 30" model the 27" will be a good buy at a great price. (there is a Hazro thread here somewhere you might want to read)
http://www.hazro.co.uk/
Money no object then just get a Dell UltraSharp U2711 27" now and be done with it. (which is unfortunately £130 overpriced on OcUK right now and can be picked up for less than £700 delivered now)
If my budget was around £200-250 I wouldn't even stretch to a 24" I would get a nice Dell ultrasharp 22" IPS panel instead.
You will need to decide if you want an IPS panel or TN and from that you will be able to decide which size you can afford.
On the other hand you may want to go for a 120Hz monitor with 3D vision if your main use is going to be gaming and video. Something like this maybe..
http://www.overclockers.co.uk/showproduct.php?prodid=MO-021-AS&groupid=17&catid=1425&subcat=
or
http://www.overclockers.co.uk/showproduct.php?prodid=MO-043-BQ&groupid=17&catid=510&subcat=
Maybe you would prefer a glossy screen for video and gaming in which case the Dells won't be any use but the up-coming Hazro 27" glossy might.
I would avoid buying a 27" size monitor that was only 1080 if you are going to be sat close to it.
(any 27" monitor that is 1080 is going to be relatively low budget anyway)
Ultimately there is a big difference in cost between a good 24" and a good 27"
Note: I know I referred to 27" monitors mostly when your thread was 24-26" but there aren't that many 26" monitors. Most are 27"
Edit:
I really should have mentioned that if you go down the larger screen and larger resolution route (2560x1440 or higher) you will have to keep in mind that you will need plenty of VRAM on your graphics card. (i.e one of the newer higher end ones) to run at a native resolution in the latest games smoothly. This is quite important and could make things very much more expensive for you. I can't say without knowing what graphics card you are running though. 1080/1200 gaming is very much easier on graphics cards these days. Worth keeping in mind and might help you decide on which screen size you need.
I hope you can pick through this post and gain some help from it.
