Dell makes a very, very, very nice 27" monitor (UltraSharp 2709W) if you think you can squeeze it in there:
http://accessories.us.dell.com/sna/products/Monitors/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=223-9379It has HDMI, DVI, DisplayPort, Component, and VGA inputs. The resolution is 1900x1200 so it fully supports 1080p. It is also a S-PVA panel, so you get nice viewing angles and good color accuracy (as opposed to the absolute junk TN panels they put out at the low end and on most HDTVs anymore). Dimensions (W x D x H): 63.21 cm (24.89") x 20.0 cm (7.87") x 45.19 cm (17.79").
Of course, even on "sale" right now, it is running $800, so...
Another option is Samsung's 2693HM 26" LCD monitor. However, this is a TN panel so it suffers the normal color and viewing angle problems associated with "cheap" LCDs. Samsung usually does a very nice job with the TN panels (so it won't be complete junk) but it won't be as nice as a good S-PVA or especially an IPS monitor. The Samsung is a bit cheaper at $500.
http://accessories.us.dell.com/sna/products/Monitors/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=A1500995Both are available right now on Dell.com.
I don't have those exact ones, but my primary display at work is a very nice 24" 16x9 S-PVA Dell monitor, and my secondary monitor is a cheaper 22" TN Samsung. I like them both a LOT.