Was waiting for all the A4000 supporters from another forum post to post here :-)
I started with the A500 for nostalgia, looking back that was a costly mistake. Finally purchased another A1200 and haven't looked back.
I realize this is an older thread but I too vote A1200. I for one bought 4 different Amiga 4000 setups including one in a tower and all of them died within a few months. My A1200 still works after all these years. I'm not saying that the A4000 wasn't a cool machine but I just haven't been able to acquire one that was in good shape.
Personally, I wish someone would come up with new hardware that was backwards compatible with the AGA chipset and I'd buy one. I agree emulation is not the same as hardware. I just wish I could boot even a PC directly into AmigaOS.
-Nyle