Another vote for the Can-am. I've had mine for several trouble-free years now, with over 3000 miles on it. Since you stated one with 4wd "for the hills" I'm assuming you want one that's more trail-oriented than work-oriented. The Kawasaki Mule you mentioned is work oriented, as are the Kubota units. They don't have the articulation, the suspension to compete with a trail-oriented machine. But good luck finding one in your stated price range....like everything else, the price has gone way up in the past 3 years. A current Can-am like mine has gone up by $10,000. And as for those advocating a Jeep instead of a side by side...I own both; I've been a Jeep Wrangler owner most of my life and still own a 2006 Rubicon. Yes, the Jeeps are nice machines. But a 100 mile ride over a rough trail in a Jeep will leave you feel like you've been pounded by a bat. That same ride on a side by side, with the soft independent suspension, is a piece of cake.
My Can-am on the mountain behind my house this past summer:
On a trail ride with a Yamaha Wolverine and a Honda Pioneer:
My Can-am on the mountain behind my house this past summer:
On a trail ride with a Yamaha Wolverine and a Honda Pioneer: