Nicholas D. Wolfwood (Trigun)
More Info: Full of Mercy
The first character that pops into my head when I think about Sanji is Wolfwood. Wolfwood is, along with Sanji, my favourite character out of just about anything and I closely relate the two of them. Just by looking at them, you can tell that they're very similar: they both have stubble on their chins, they're both chain smokers and they both go around wearing black suits. There is even two pictures that, when placed side-by-side, look identical! (Click here to see.)
Wolfwood and Sanji's attitudes are the same too. While Wolfwood leads a rougher life than Sanji, he still has his goofy moments and he too shares a rivalry with another male member of the cast (Vash the Stampede). They both can be light-hearted at times but when things get serious, so do they. In fact, they both share the exact same "I'm going to kick your ass" attitude while fighting and they both exude that really cool, badass attitude while in battle or when surrounded by strangers. Heck, even their poses are the same most of the time -- leaning back slightly with their hands in their pockets!
Furthermore, Wolfwood and Sanji both have alter-egos. Sanji's is Mr. Prince, an identity that brings out the more violent, destructive side of him where Wolfwood is Chapel, a member of the deadly assassin group, the GUNG HO GUNS. Both guys have had scarring childhood experiences (neither of them have parents in their lives). I'd say the only big differences between the two are their fighting styles (Wolfwood uses guns, Sanji uses his legs) and their professions (Wolfwood a priest, Sanji a cook).
Spike Spiegel (Cowboy Bebop)
More Info: Bang!
Like Wolfwood, Spike shares a similar appearance to Sanji. Both are chain smokers and both wear suits all the time. Aside from smoking and their attire, they also have the same sort of stance/pose where they're usually leaning back slightly with their hands in their pockets. Not much else can be said about their appearances -- the similarities stop there.
Their personalities, however, are more similar. They both have a really relaxed attitude but they also have tempers as well. Sanji has a tendancy to be more goofy than Spike, but Spike has his moments too. Both are fairly stubborn men. Moreover, what makes Sanji and Spike even more similar is their fighting style. While Spike uses a gun, he's also a martial artist, just as Sanji is, even though Spike tends to use more than just his legs in the process.
Sohma Yuki (Fruits Basket)
More Info: Himitsu
Yuki is definately not a character you would associate with Sanji at all... the two don't look anything alike. They do share really similar personalities though. Yuki is a bit more serious than Sanji but like the pirate cook, Yuki will become very angry if his manhood or ability to protect someone or something comes into question. He's also very chivalrous, especially in regards to Tohru -- he would do anything for her, just as Sanji would for Nami.
Yuki is also a powerful martial artist, just as Sanji is. Although, like Spike, Yuki tends to his more than just his legs in a fight. Interestingly enough, Yuki is known at his school as "Prince," just as Sanji uses "Mr. Prince" as an alter-ego.
Hatake Kakashi (Naruto)
More Info: Freaky Eye
Kakashi and Sanji share a number of similarities... first being their appearance: they both have hair that's swept over to the right and you rarely see their right eye (or in Sanji's case, never). Of course, that's about it in terms of appearance that they share a likeness for. ^^; Second is that Kakashi is also a martial artist, although not quite on the same level as Sanji as he tends to use ninjutsu techniques more often.
Personality-wise, both are.. uh.. ladies men, to put it nicely. While Sanji prefers to actually chase the girls, Kakashi is always seen reading one of the novels in the Icha Icha Paradise series (well known for being adults-only). They're both also very laid back, Kakashi a bit more than Sanji, but they also have their goofy moments among their serious ones. To both men, protecting their nakama is most important and they become quite dangerous when their loved ones are in danger.
Norris (Chrono Cross)
More Info: None.
Both Norris and Sanji don't really have much in common at all in terms of personality... but they sure do look alike. They both have blonde hair and have the same hairstyle; short with bangs that sweep over to the right side of their face. They certainly could be mistaken for brothers or maybe even twins. XD On top of that, Norris also acted out the role of a chef when he infiltrated El Nido at Viper Manor. He even appears in a chef costume! :D
Raychel (Tasukiland)
More Info: XP
This is my friend Raychel. She usually doesn't look like Sanji and she's not like Sanji at all. She sucks at cooking. But she looks like him in this picture. OMGKTHXBYE