Genre kings come and go in this business, either because those games failed to change with the times and their imitators have not, OR because their successors were just that much better.
But there are games that have remained fixed on their respective thrones for an obscenely long time, inversely, because the competition just sucks or due to the one harsh truth that perfection simply cannot be improved upon.
That right there is my pick. Released in 2005 and has kept the crown since.
For those of you lamenting over the old WWF/WCW games on the N64, let me say I was once one of you. I thought the genre was dead for good, buried forever inside a coffin hand-built by Yukes. Then I downloaded this little title begrudgingly, along with the accompanying WCW/WWF/ECW packs from another site, and played around with it one weekend...
There's no going back. Hell, there's no going forward. Hands down, the best wrestling game in existence. With the extra packs, you get virtually all the wrestlers, their moves, finishers, and even entrance themes.
https://youtu.be/uPoEBmgzGB0?t=1m27s (WWF Attitude 1998)
2005.
12 years, the undisputed king of wrestling games.