I have to say Orton. I like both Orton and Batista, especially their 2005-2010 years. In fact, Orton was my favorite guy back then. With that said, Orton is miles ahead in the ring (probably in the top 10 performers ever) and is decent on the mic. So, as far as in ring performance goes, Orton has the upper hand.
Come on now. Randy Orton isn't a top 10 performer TODAY. He's never been a top 10 active performer at any point in his career. He's barely top 10 in his own family all time. He has Batista beat, sure, but that's not saying much...it's like saying Batista is light years ahead of Orton on the mic. It's not something to brag about.
Yeah, Orton's 2009 was so amazing and nothing Batista has done comes close to that. In fact, Orton at 2009 is one of the best storylines WWE has pulled out during that decade.
It was one of the best storylines during the decade, for sure. Unfortunately, an even better one was the rise of Batista in 2004-2005. That obliterates anything Orton has ever done or could ever dream of doing. It wasn't just one of heel go best of the decade, it was one of thr best in the history of pro wrestling.
To answer the question, Batista hit a peak that Orton will never approach. That very few in the history of the business will ever approach. Batista was THE face of the company for awhile. Yes, even ahead of Cena briefly. Remember, Batista won the Royal Rumble instead of Cena in 2005, and Batista was the one who main eventer WrestleMania 21 instead of Cena, when they were both winning their first world title. Obviously, Cena caught up with him shortly thereafter, and kind of pulled ahead when Batista got hurt the next year...but Batista was always a very strong #2, or a 1A. That's something Orton just can't claim. His face run was a disaster, there's no doubt about that. He wasn't just behind Cena, he was behind Sheamus as well. Think about that. Sheamus was a bigger face than him.
On the other hand, Orton has the longevity. While there have been times that Orton was suspended, and times when he was depushed and put in midcard tag teams with Edge, he's never taken a significant amount of time off.
So do you take a 10 year career with ups and downs, or a 6 year career that hit an incredible height but disappeared of the face of the Earth? I won't tell somebody they're wrong to taking the former, but give me the latter any day. I'll take the face of the company, even if he's not around as long.