I wish someone would report back on the larger Dells. I saw a link on toms hardware the other day for a dell 24" with good specs for around $275 or so of I recall. Just did not want to chance it...
Bigger monitors doesn't look so hot with a native Amiga's output (eg 320x240). I'm currently using a 24" BenQ which is ok but makes everything look a bit blocky. As soon as I can get an IndivisionAGA Mrk2 I will swap to my 21" model which is probably as big as you'd want to go (19" is probably better to be honest).