Hi,
I am planning 2 new monitors (screens). I had 2 X19" , I was thinking about buying 2 X 24"
Does anybody have a recommendation about size? As big as possible maybe?
Let me know your experience, also if you have sen a good price offer 
Thanx,
Are you using speakers?
yes, blue sky with sub, speakers are on stands
Only thing with two 24" monitors side by side is the speaker positions may be a bit wide! I have mine one on top of each other and a third off to the left outside the speaker positions (for control room stuff and the odd plugin). When setting it all up, the speaker positions are of the utmost importance for the most accurate monitoring you can manage! Everything else is secondary to that IMO.
Contrary to some opinions I find two 24" monitors set up like that very comfortable and easy to view.