I think this place needs a thread about stats, I recently started (only soul level 24) so I'm not in a position to give out recommendations, but I wouldn't mind getting some pointers ;) So far my highest stat is str so I could use this Bastard Sword I found. 
 
Which do you guys reckon is the most important stat? Which ones are the worst? What should you avoid?

i guess it all depends on which class you start out with, and what your intentions are for the build you make - i started out with a wanderer and currently sit about soul level 70. 
 
I may have slightly gimped my character when i threw a load of stats into magic and intelligence in order to learn a miracle or two and a couple of spells (mainly the big ass fiery equivalent to gods wrath which dominates groups and PVP), but since then have added a ton to vitality, and strength, with dexterity and endurance getting the odd one or two points, and luck being a high stat anyway. 
I'll definitely pay more attention on my next run through 

it seems inevitable that you gimp your first char really since you have no idea what's good or not..

" it seems inevitable that you gimp your first char really since you have no idea what's good or not.. "

Yeah for sure, especially since it gets harder after each play through :P

I'm still using my first. The one thing I regret is putting a few points into luck (14) otherwise I am quite happy.
 
I think the best recommendation "early game" is to get the Demonbrandt then upgrade it to the NR. It's power is insane and it doesnt level with stats so you can focus on VIT (open end, returns diminish after50 I think) and END (to 40).
 
Plus of course the lava bow, so you don't have to pump STR and DEX to get good damage.

" Yeah for sure, especially since it gets harder after each play through :P "

My char started as Royalty and I guess it fits my playstyle a bit, I tend to be very careful most of the time and take it slow and safe, starting with a spell and a ring with mana regen really fits well as kiting and casting seems to be pretty effective, although this could change (only finished 1-1 and 1-2 so far) 
 
Also I killed the dragon using magic, took maybe 2 - 3 full mana pool regens or so, it took a while, which I didn't though mind as I just watched tv while it regened, lol :) But I'm enjoying the melee combat much more then just cheesing the whole level casting from max range and retreating all the time.. (Plus that takes so much longer to do then just rushing in and killing everything with a wide swing) 
 
So far I have a +3 Spear (can't remember which one, got it pretty early) and a +3 Bastard Sword (I think it was) and not entirely sure how to proceed.

I just got my platinum trophy and used a faith based character.
 
You can still go melee with strong spells. Just use Crescent and Moon weapons. Get 40 endurance for max stamina and around 40 vitality. I would recommend 16 in faith so you can cast Anti Magic (incredibly useful in 3-x)  and Second Chance (Lets you revive with half health if you die to an enemy).
 
Intellect atleast 15 so you can cast fire storm and second chance once. 30 intellect lets you cast twice.
 
If you wan't to use one of the best shields in the game you need 22 strength. But you could also only put 16 in strength and use the Dark Silver shield wich also is great. 
 
The rest put in magic. Since your spell power and weapon magic damage will come from that stat.
 
Early game I would try to get the Crescent falchion from 4-1 or even better the Dragon Longsword from 2-2. Dragon Longsword does not scale with stats and will be a great weapon through the entire first playthrough. I upgraded from a Dragon Longsword +5 to a Blessed Knight sword +5 in my second playthrough.  I wanted to go one handed and shield and Longswords/Knight swords have a "poke" attack on R2 wich lets you attack in narrow corridors and other places where wide swings aren't that great.
 
Also check: 
http://demonssouls.wikidot.com/
 
and here is a YouTube walkthrough if you are having serious trouble anywhere:
 
 http://www.youtube.com/view_play_list?p=A34510718457B43C
 
Don't use the walkthrough until you have tried for yourself though!

One great thing about demon's souls is that you can custom tailor your weapons to do what you want. Have super high dex? no problem, use some blade stone on something and make it work for you... Have a decent balance of stats? Cool, make a moon winged spear and stab people from 10 feet away...  I would say every character should have a base of 22 strength, and 18 dex to be able to use the purple flame shield and compound long bow as they are incredibly useful for some levels where your pure mage might suck shit... /shrug 
 
Just don't do what I did and get obsessed with endurance and neglect all of your other stats. 

PFS is beyond useless :p
 
Go steel or knight depending if you want to parry. If you don't really use shields like meself go adjudicator and never again worry about poisoning. nice.

I like balancing my stats, but I won't have them all at the same number. I prefer swords and bows over magic, so my magic stats aren't too high, while my strength, endurance, and vitality are stronger. I see how much each one will benefit me when I go to upgrade. The one that seems the best to me, I will get. Also, if one stat is much lower than the others, I'll put my souls on that stat.

" PFS is beyond useless :p  Go steel or knight depending if you want to parry. If you don't really use shields like meself go adjudicator and never again worry about poisoning. nice. "

I honestly don't think it makes a lot of sense to increase stats just for using the PFS. The steel shield eats just as much force and it's reqts are much lower. It also weighs less and allows you to focus on other equipment.
 
Granted, once you get to a really high soul level those things may not matter that much, but in the juicy pvp range around 120-150 they certainly do.
 
And the dark silver's guard I can break with an airplane plastic fork.

I'm on your friends list mdss. Red stone. I'll be happy to demonstrate XD

It depends on the application. Assuming you are going to use a shield i'll take the adjucater, dark silver, or PFS depending on what I am doing. If I am going to tank flamelurker i'll bring the PFS, if I am going to fight old monk i'll bring the dark silver, if i'm pvping i'll go 2 hand hyper mode and pop the adjucater for regen.

Do me a favor and perform this simple test:
 
1. Upgrade the steel shield as far as your hardstones take you without hurting other more important upgrades you may be planning.
 
2. Go to 4-1, keep the shield up and walk up to a skeleton. 
 
That felt good just now, didn't it?
 
Now, repeat with your DSS+5. 
 
Ouch, that wasn't as fun, was it?
 
I know you can do the same with the PFS.  But why invest all those stats?
 
For tanking Flamey I would suggest the LBS btw!!

There is no worst stat.  They're all good for something.  A stat is only bad when your class has no need for it.
 
Having said that though, it never hurts to put points into Vitality, Endurance, or Luck, no matter what class you are.