[MasterSplinter]

Which is better all around. 3 jaw. 4 jaw or dt chuck?

 

[NCPaladin]

For woodturning you want a four jaw scroll chuck. Three jaw is typically metal turning; there are also four jaw metal turning. A would turning chuck will have jaws at close to a completer circle.
Whether it is dovetail jaws or not depends on the maker. Mine are Nova's and on most of the jaws the inside are smooth, corrugated, or has a small lip. On the very largest jaws the inside has a dovetail. I think all of their jaws have dovetails on the outside.
Other makes may have straight smooth jaws inside and out or serrated jaws inside and out.

 

[Dave Paine]

+1 4 jaw scroll chuck is what you want for woodturning. The 3 jaw is common for metal working. I do not know why.

Most chuck manufacturers offer smooth jaws which typically are dovetailed or some type of serrated.

The dovetail jaws need the tenon to be cut at the slight dovetail angle.

The serrated jaws use a 90 deg tenon, but will leave a mark on the wood.

Some folks feel the dovetail jaws hold better.

When I am coring I am finding the dovetail hold the blanks better than my serrated jaws.

 

[Bill White 2]

I use the Grizz Vicmarc clone with DTs inside and out with good results.
The ribbed jaws are sometimes difficult when rechecking. They tend to misalign.
Bill

 

[Maylar]

3 jaw chucks are good for round or hex stock but will not handle squares. Woodturners often start with squares, so a 4 jaw is the right choice.