what is better:soul calibuur or street fighter?

What's better? Apples or a Bulldozer.

Completely incomparable, they are completely different games with completely different playstyles.

Soul Calibur is a worse fighting game. But there is more shit to do.
Street fighter is a less complete package. But the fighting is 100 times better and the net code is flawless.

street fighter hands down.

Keyhunter pretty much explained it.

However I'll always prefer Soul since that's what I grew up with, and I'm hopeless with SF.

Just because they are fighting games doesn't mean that they are similar. They are two very different games, and comparing them is stupid.

Most of the people on this site are only casual to the fighting genre. In other words, there are aspects about fighting games that they don't understand. I don't blame because they're not that big into the genre.

I suck at both.  I button-mash my way through both (not an option in VF series).  Soul Caliber is more fun for my reckless play style.  Soul Caliber has many character customization options which I like.  Street Fighter bought my soul in quarters in the late 80's.  It is a better attuned fighting game than Soul Caliber.  If I was inclined to learn how to play, I'd probably prefer Street Fighter, but I'm lazy so Soul Caliber satisfies my needs more. 

So, the answer to your question is relative to what you are precisely asking.  Street Fighter is a better game, but Soul Caliber is a better game for me.

They are very different and hard to compare in my opinion. I love them both and find them to be great for different moods, but if I had to pick only one...I'd pick SCIV only because I find the SP more enjoyable and I play fighters SP more than MP. I'd give SFIV the edge when it comes to MP though. (and yes, I know that the question relates to the series as a whole, but I prefer to answer the question using the most recent games in each franchise)

Street Fighter is way too much of a hardcore fighting game for me to get into, I can play a few rounds of soul calibur and still have fun

Street fighter is the superior game, but I can still have fun with Soul Calibur.