You can't say with that any semblance of objectivity.Sadly, Batista - he was constantly in the main event and was inexplicably popular. I struggle to understand why. Fair enough, he looked good and his character was credible. Unfortunatley, all of his matches were dreadful. His wrestling style never appealled to me. I always thought he was overrated and undeserving of his spot. I guess WWE needed a monster after Lesnar left.
The way that people talk about Batista on this forum makes me wonder of I'm missing something. Tonight I'll go back and watch some his biggest matches / most talked about matches and see if I can find some redeemable quality that I'd overlooked previously. To me he was just a jacked up, toned down, 21st Century Ultimate Warrior.
Batista vs. Christian - Raw 2005
Batista vs. Triple H - Vengeance 2005
Batista vs. JBL - Summerslam 2005
Batista vs. Eddie Guerrero - No Mercy 2005
Batista vs. Undertaker - Wrestlemania 23, Backlash 2007, Smackdown 2007, Cyber Sunday 2007, Survivor Series 2007
Batista vs. Edge - Vengeance 2007, Night of Champions 2008
Batista vs. Shawn Michaels - Backlash 2008, One Night Stand 2008
Batista vs. Cena - Summerslam 2008, Wrestlemania 26, Extreme Rules 2010, Over The Limit 2010
Batista vs. MVP - Smackdown Series (most notably the No DQ match)
Batista vs. Kane - Smackdown 2007, Last Man Standing 2007
Batista vs. Randy Orton - Armageddon 2008
Batista vs. Chris Jericho - Raw 2008 (in May I think), Cyber Sunday 2008
Batista vs. CM Punk - Great American Bash 2008, Raw 2008
A mixture of good and great matches. He has even more when taking into account tag matches or with more than two men involved. And if you want matches with lesser known stars at the time, check out his work with Dolph, Ted Dibiase, Morrison, Burke etc. He even gave those men pretty good matches although they were short (looking around 8 - 10 minutes).
Batista is far from being dreadful in the ring. For a big man, he was good, and in 2007 especially, he was great. If anything, his age and size worked against him because you can see him slowing down throughout 2008 quite noticeably.
The most important part of becoming a star is charisma/presence. Batista screamed "big-time" in 2005. Since then, he improved in the ring, on the mic, and as a pro-wrestler overall.
If I was to compare Orton and Batista's talents, I'd give Batista every category except for in-ring skills. He's far more charismatic, has much more of a presence, is a bigger draw, was a better/bigger face, and he proved he can be a great heel too. On the subject of in-ring skills, I'd say Batista has many more memorable matches to his career than Randy Orton. That may be partly due to the fact he was a much bigger star though.