What do you guys think is the best one for making a fully functional website? What do you personally use from the scripts?

PostNuke. Try it. Or, If I were you, I will just create a website from scratch. If you are creating a website for an organization, use PostNuke.

When you are making a website for a big organisation, It is quite recommeded you make a script from scratch for that organisation keeping in mind, what they want out of their website. Using Readymade scripts is recommended in most of the cases.. but they might not be able to provide what a user or Organisation wants.

I had a client who wanted to make a forum like system and was interested in healthcare. He was a doctor and wanted to make a site for them... Well, his requirements were very similar to that of a forum system but some things were not possible. Eg. He wanted detailed statistics of all the members, patients that had signed up.. He wanted to categorise members in two parts.. doctors and patients. And wanted to treat the patients and help them online. he wanted stats regarding how many were successfully helped.. etc. He wanted to categorise doctors etc on the basis of their field and speciality in a particular subject.. Even though the system he wanted was quite similar to a forum.. When I installed it and showed it to him, he was not quite satisfied.
But, readymade scripts do work out fine, if you have less time in hand, or your client is giving you some pennies

what do you think the fundemental differances are between postnuke and phpnuke...ive tried/used both and still dont know which is better...i like postnuke's interface better but it seems there is less mods and stuff for it.

I think POst nuk rocks but have no clue to set it up if i did i would be using it in a sec cuz yah but i ahve a Q about that is it hocked up to your forum and all because i really want to use it that why i am posting here now so i can try to get postnuk and stuff up. but i have no clue how to set up skins. But yah difenatly go postnuk.

You can set up the postnuke site from cpanel. And than use the web admin for postnuke and you can setup your forums in the admin panel of your new site.

I'm really not the fan of readymade scripts. Everyone can view their code and they can easily find a bug and crash your site. If you write your own script, only you now for the bugs and you are not that crazy to deface your own site So, the point is - if you want to have a good, functional web-site you are the only one who can make it. Noone will make it for you.
But, I can assume that there aren't much people who are interested in programming. If you are one of them, here is the first step what you should do. Find the script you want to use, search the google for all bugs of that script and try to fix them. This way, you are protected from "script kiddies" who are, in most of the time, the main security problem for Webmasters.

I hope I helped you.

P.S. Sorry for grammar mistakes