Lightning Reflexes and Iron Will(along with their Improved counterpart). Rogues do not have the feats to pull this off unless they are willing to sacrifice other feats. The best they can do is invest in Ioun Stones, Headbands/Belts, Cloak of Resistance or not be targeted in the first place.
The Rogue needs to invest on all his abilities as he is the skill monkey. This is where they shine.
Fighter only needs to invest in Str and Dex. Why would he need Con as he already has 1d10 HP and Fortitude is his best saving throw? He would be better to invest in better armor in the long run.
I've seldom seen Fighters invest heavily in Save feats. Usually their feats are all spent on combat, especially since so many good feats requires a bunch of others. Rogues also gets a few combat feats from their Talents now to help compensate. And after the few essentials (Improved Initative, Weapon Finesse, maybe Weapon Focus) they can spare a feat just like the fighter. Not that I would, I like to play characters with weaknesses.
A Rogue that tries to be good at everything will probably be mediocre at best. They can get decent scout skills, or superb traps/locks skills, and are almost always good at stealth. Yes, someone with say 18 dex and maxed out Stealth is good and many monsters will have a hard time to spot him.
Strength is probably the least useful stat for a skill rogue, and they don't need as much in mental stats as spellcasters do. The only thing they really need alot in is Dex really, the rest can be 12-14 with possibly one dump stat. The very successful combat rogue in my group has 7 charisma and he still makes do.
A fighter with 18 str, 14 dex and 8 con is not very good. d10 is only one average more than the rogue's d8 and the Fighters usually needs tons of HPs to be able to tank effectively. A rogue does not need to tank effectively. Also a fighter limits himself by having less than 13 Int and will have weak Will save and perception by dumping wisdom. Cha is pretty much the only thing that is mechanically "safe" to dump, although many like to play charismatic leaders, good intimidators etc. as fighters.
The only thing they have an advantage in save-wise is the bonus vs Fear, which is not so common or dangerous as other Will-attacks. The Rogue's Slippery Mind as mentioned is far better. And what does armor have to do with this? And having a good base save doesen't mean you want to dump Con, or the rogue could outdo you in fortitude saves! A 3rd level Rogue with 14 con will outdo a 3rd level fighter with 8 con.
A fighter with good Con however will get a formiddable fortitude save (and those are important enough to invest in!), and more importantly HPs. I would probably never start a fighter with less than 12 Con, they simply would not last.
Not to mention all the threads about bards being useless ...
In my opinion, rogues have two major flaws in Pathfinder:
1. They don't hit.
2. They aren't that good in stealth.
They were also very soft targets but with the change to offensive defense at least this problem got much smaller.
Any other class with a good or medium BAB has some ways to increase its chance of hitting. Some people could argue that rogues have the option to flank an enemy or catch him flatfooted, but any other character can do so, too, on top of their other bonuses.
So too fix the rogue, he'd need improved stealth to bring him on par with the ranger, as well as some rogue talents that increase his chance of hitting.
1. They hit. Just not as often as Fighters. Or Barbarians when raging. Or Ranger's against favored enemies. Which is ok in my book as those classes are supposed to be better at fighting anyway.
2. ? Compared to what? They even have a Talent that improves Stealth. Rangers are better in their "turf", and they are fairly equal in dungeons. Also, TWF rangers needs more strength to deal enough damage as they lack Sneak attack, so Rogues can pump more into Dexterity without loosing too much combat ability.
And in any case anyone with Dex as prime stat and Stealth as class skill can become excellent at Stealth, the Rogue is no exception, and has the skill points to spare.