Dash or underscore for space in nice URL

I have a question regarding the spaces in nice URL-s , I am coding a new site
and for URL I will use complete title so I was wondering what should I use for spaces '-' or '_' do anybody know what is preferred
eg

/review/Best-Tennis-Rackets.html
//or
/review/Best_Tennis_Rackets.html

Code (markup):

 

I think it's best to go with dashes, although I have had success using underscores as well. I think some engines treat this differently, i.e.

Hyphens: "these-are-treated-as-seperate-words"

Underscores: "this_is_treated_as_a_whole_word"

That help?

 

That's right stick to dashes. They get indexed pretty quickly.

 

thanks guys I will go with dash version

 

i think this is right answer for this question,

 

Use hypens..

/review/Best-Tennis-Rackets.html

 

I think better to use dash instead of underscore, As matt disscussed here

http://www.mattcutts.com/blog/dashes-vs-underscores/

 

always use hypen (-) because it is very useful for optimization. i mostly prefer for hypen.

 

i've seen this on several domains in search results and it is best to go with the hyphen in my experience. Never have a I seen a underscore outperform. I'm sure there are exceptions to the rule but isn't there with everything?

 

hyphen makes kywords separate in se point of view, and underscore makes them as a one word,

hows that?

 

Agreed. Go with the dash!

 

Wow, I completely forgot about the underscore doing that. Haven't had to do that since I used HotBot for a search engine...lol

 

Underscore vs hyphen, does this answer your question ?

I don't think it matters much though you should go for hyphen as its a word seperator