1) Nick Ring - He's got his own sort of oddball pro-wrestling style persona. He's not the type of guy that has one hit power that will make Punk tentative for his first fight.
2) Kevin Casey - He'll be coming off suspension around the same time IIRC, and could be a very interesting matchup on the ground.
3) Andrew Craig - A really solid fighter to have to go up against first, but could really show what level Punk will be entering the UFC at.
Now for the 2 outside matches I am thinking of where CM Punk would probably be vastly outmatched, but would probably have more name push behind it.
4) Uriah Hall - Everyone that's an MMA fan knows about Hall's crazy KO on TuF, can he make a highlight reel out of a former WWE star?
5) Rich Franklin - Franklin has one fight left, and said if the right fight came along he'd be more than happy to fulfil it. Well, what about a fight for him that would have the biggest PPV buys of his career? That'd be a helluva way for him to walk off into the sunset.
Not best if they want him to win lol. They would all run through him.
ProctorMMA - Not best if they want him to win lol. They would all run through him.
There isn't a single guy in the UFC's middleweight division who wouldn't.
Rich Franklin sounds amazing 
http://www.bloodyelbow.com/2014/12/7/7347719/dana-white-to-bring-cm-punk-up-slowly-hes-going-to-fight-a-guy-who-is
He told ESPN about it:
"He wanted to fight here," White told ESPN.com. "He wanted to give it a shot, so we gave him an opportunity. It's not like Brock Lesnar. We're not going to throw the kitchen sink at him. Lesnar had a wrestling background. [CM Punk] is going to fight a guy who is 1-0, 1-1, 2-1 -- something like that.
So, they are just going to sign guys to single fight deals, to come in and lose to CM
thatonedude - Whoever he fights it better not cost $60 to watch him get beat up.
I predict he'll be the opening fight of the PPV on July 4th weekend. Probably with a Winner of Jones/Cormier title defense on the card as well.
I'm liking the rich franklin idea tbh
They could sign an 18 year old wrestler to come beat his ass. This shits a joke.
horsemeat grew my head - I'm liking the rich franklin idea tbh
I have to admit, it would be nice to see Ace end his career with another Quarry-style highlight.
Even though I put Franklin last, that was my favorite fight that I had on the list. I love Rich, and I'd love to see him make a nice payday on he way out.
He's never had an mma fight. 
Baroni, Burkman, Karo Parisyan, Tamdan the Barn Cat Mcrory, Daniel Pruder, Frank Shamrock, Miletich, Serra, Hughes, Sakuraba, Shonie Carter...somebody 30s-40s maybe retired and who'll make a good show of it