Hi.
Is there another pack of sounds and tools that can compete with Native Instruments? I am really thinking of buying v10. But if there is something better out there I want to know. Of course price has a saying, but it doesn't need to have so many modules and sounds. Only that they sounds great. Any thoughts?

I think it's a great value, and unmatched by anything else.  K10 has pretty much everything you could want ... you could spend weeks just trying out everything in the package. 
 
Given that Kontakt by itself lists for $400, the fact that you get everything else for just an additional $100 is mind-boggling. 
 
Cheers,
Eddie
 

Even if you didn't think all the modules are "necessary", you would probably pay close to Komplete's price with single buys for the stuff you would use ...but you would probably get less than 50% of what Komplete has.
Granted some would be (arguably) better, but you would not have as many options/choices. 
 
Definitely worth it, but plan to spend all afternoon loading everything in!

What I want is action strings and session strings. Plus more options of sound. Digital sound factory isn't good enough. And complete can give me a little click of inspiration. Is action strings really the best? And session strings?

I think Komplete is pretty great, particularly since Kontakt is kinda the thing for samples. Well, this gets you Kontakt plus a bunch o' extras so it is a great way to go.
 
I don't much care for action or session strings, but having Kontakt I could, and did, get Kirk Hunter Concert Strings 2 which I like a whole lot.

I don't think Action strings is that great a package.  if you have nothing string wise right now, sure it's something to start with but it's not that great a package.
 
is Komplete worth it?  yeah worth every penny.  Guitar Rig 5, Massive synth, Battery drums, Kontakt, Evolve libraries, Komplete has a ton of toys to play with.  Komplete or even Komplete Ultimate.
 
I bought Komplete 8 and upgraded to Komplete 9 Ultimate.  I will be upgrading to Komplete 10 Ultimate.
 
Once you have Kontakt full version your options open up to some amazing libraries.

I'm not saying it is not a good buy but I don't really use the majority of the things that came in Komplete and probably never will.  Kontakt is my main NI tool and I had already purchased the packages that I wanted so I didn't gain a lot except less free drive space.
 
I purchased K9 because of the killer upgrade sale for $199 a while back but will not be upgrading to K10.

I think Action Strings is pretty limited in terms of what it does. Session Strings is pretty decent however - it's not an orchestral library of course but I've managed to wring some nice string parts out of it. Once you get the hang of the key switches it's quite versatile. 
 
I wouldn't buy Komplete for the strings though. It's worth it just to get the full versions of Kontakt and Reaktor, let alone things like FM8 and Massive. 

The VSL strings in the Kontakt factory library are better the DSF strings IMHO.

The stepping stone method or crossgrade to Komplete is the way to go and there is usually two sales a year at least with 50% off. Buying it during a major release is normally the worst time even if you own previous versions.