Problems with Google Calendars and iCal in Lion
BusyCal is the best answer I can give you if you only want to sync calendars to Google.

I would also highly recommend SpanningSync which will also sync your Contacts in a much better and more reliable manner than Address Book will.


  (I have no affiliation with either company, and am a paying customer/user of both. I use/love BusyCal for my calendar, but I sync with MobileMe not gCal… I use SpanningSync to sync my contacts to Gmail. I have written reviews for both Spanning Sync and BusyCal.)