I'm a bigger fan of the older stuff though i have to say i like the Z4's 'flame surfacing' styling.
The new 7 is challenging and not as easy on the eye as the old one, though on big wheels it does look good imo.
The new 5 is a mess, the X3's strange angles make it look like a concept car and not a finished article; the (new) 6 also looks clumsy though i'll have to see the X3 and 6 in the flesh before i make up my mind definitively.
All in all i prefer the older stuff but hey, design moves on. I didnt like the E46 when it came out and now i do, so i may change my mind about the new stuff. Im sure many will.