I have owned every Amiga model apart from the CDTV and the A4000T (I don't count my towerised A4000 desktop as a true tower), and the A3000 is my absolute favourite. If you look at the standard, out-of-the-factory specs and looks, it's just the best one that Commodore ever made. SCSI and flickerfixer onboard, and it looks awesome.
Apart from that, the A4000(T) is my favourite when it comes to expandability, and the A500 for a good oldschool gaming experience. The A1200 is a bit better than the A500, but I just don't like the looks of it. They took the wedge too far with that design (maybe I'm just gonna put my A1200 mainboard in an A500 case - best of both worlds! :-))