I was going to say the old 16" E39 528i rims which have those thin groves between the many spokes, but the M3 wheels above must be a nightmare - basically any wheel that has thin tight spaces, and lots of them!
Interestingly I find that my new wheels are not as easy to clean as my original wheels - the five V-spoke design is what makes it a bit tricky, but I think it's more to do with the condition of these wheels that makes it tricky. Lots of burnt on brake dust and contamination that needs to be removed.
The old 330i wheels are also ten spokes, but very easy to work with and since there are no or few "edges" it is very straight forward to clean - paint work is in good condition and kept clean which helps a lot!!!