This is pretending Silva today went back 17 years or so back in time
I would have to say Mark Coleman. I wouldn't go as far as saying that Coleman's takedowns were Sonnen level but his ground and pound was just as brutal
As for Gracie, I think he would have had a hard time submitting Silva and would eventually have gotten annihilated in the clinch
As for Shamrock, even though his BJJ defense greatly improved after the first fight with Gracie, I think Silva's length would have been too much for him to deal with
A fight with Patrick Smith would have been exciting stand up war for a few minutes
Holy unholy! That is an intriguing question; but what makes it better/worse is that you've already made the picks that I thought of as I was reading the list of latest threads BEFORE I clicked the link.
Considering the 'old UFC' had no weight divisions; I think a prime Coleman and Shamrock would be the first two candidates that come to mind (prime Tito could take a beating but would get finished.) You have to respect Gracie because of how he -perhaps single handedly- revolutionised martial arts for the first time in like 20 years (after Bruce Lee died) but he'd get killed by today's Silva (pre-Weidman; and perhaps even now) as I doubt he'd survive long enough to Ryo-Chonan Silva who wouldn't have any of that,
"I'll let you take me down and sub me because I think that Judo stuff sucks and doesn't work in real life; what do you call it again; BAZILLIONJOOCHEETSU" attitue popular pre-1993. At best, he'd bully him like he did Maia and stand with his hands on his hips as he did with Leites.
Mind you, every fighter mentioned IMHO would have the great/significant -CHANCE- to beat Silva; but Silva would win regardless. Can I say prime Chuck? (I know he wasn't at UFC 1 but his time at the top was finishing as Silva's was starting) At one point he didn't have a glass-jaw; and he could KO anyone they placed in front of him. What Wiedman did; Liddell; if connencted could have done harder. However, even that would depend on whether Silva would keep his hands up or not.
I have a name; actually three, I'm just going to throw them out.
1. This one is not one I'd expect to win by any other means than a flash KO that nobody -even the fighter himself- saw coming: Jason Delucia. Why? I have no clue.
2. Wes Albritton. He lost his only UFC, and overall MMA fight with Tito Ortiz; saying he would try to keep it standing but when it started he immediately walked into a tie up clinch-grapple with Ortiz; who pressured through, mounted him and pounded him to a TKO. Why pick a guy who's 0-1 in MMA? Two reasons, one, we never actually got to see him strike; and he had black belts and Karate, TaeKwonDo (as does Silva) and practed Kickboxing; which owes part of it's hetiage to Muay Thai, which Silva is apparently a whiz at implementing. Two; pure nonsensical superstition: his record before the after his fight with Ortiz is the same as Weidman's record after he KO'ed Silva; except backwards. Weidman's at 10-0 and Albritton's at 0-1.
3. Tank Abbot. Remember at one point, this 'original' Huntington Beach Bad Boy; actually had some 'cred.' Before he ruined it by never-training, calling real martial artists 'Karate ***s' and by losing more fights than he won. Why would he beat a prime silva? Silva saw how miscordinated his next opponent was; decided he didn't need to train -or make weight; as I'm not sure they had weight divisions back then- and fattened himself up to the point he walked in; tired, because he stayed up all night trying to watch every South Park episode on multiple monitors as a hand-eye coordination training excercise cooked up by the Blackhouse members as a joke, went to sleep when Buffer announced his name thinking "Fuck, it's tank abbot? I'm not staying awake for this; yeah, I don't care if it's my own fight; I need my rest." Tank then sat on him, the referee counted to 3 and forgot this wasn't fake-TV wrestling; which is where Tank performed most of his best MMA matches.
Okay; now two 'serious' suggestions.
Can I suggest someone whom almost everyone overlooks. He's got -perhaps not the best record- but not the worst either. It's been a number of years; so I'm not sure if he's eligible but I'd like to say Ron Waterman. They guy is a genuine Superheavyweight and he can be mistaken for Scott Stiener. I think Mark Colman could have done it; but I think Waterman could have done the same to Coleman. Therefore I'd like to throw my vote in; and say Waterman could have done it; if he forced on him early -like the first 10; any later than that he'll lose a decision- and hammer-fisted untill the ref stepped in.
Again, I'm not sure he's eligible based on what period he was fighiting in; but the late great Evan Tanner is probably the best bet. If anyone in the old UFC could have done it, it'd be him; I don't know how, I just know it could have been him.
If you think any of the suggestions I made earlier, sucked; just remember this: Anderson Silva once lost to Daiju Takase; a fighter from Japan who, going into his match with Silva had 4wins-7losses. And he defeated Silva via Traingle Choke. So stranger things have happened than Tank Abbot possibly getting a win over the greatest fighter in the world.