<p>For best performance, is it better to use a virtual IDE HDD or virtual SCSI HDD?
If, SCSI, does it matter whether you use an BusLogic or LSILogic?</p>

Go for the SCSI and LSILogic. IDE and BusLogic are for compatibility reasons. Like when you do physical2virtual...
There's a whitepaper from vmware showing the difference between LSILogic and BusLogic, which in my opinion is rather small:
http://www.vmware.com/pdf/ESX2_Storage_Performance.pdf
Edit after like three years:
With current ESX environments it's best to use the Paravirtual SCSI device.