Wet or dry are your choices. Dry gloves are very bulky and awkward, but potentially the warmest. However, air needs to be able to travel into them from your suit or they'll compress to uselessness on descent. Ring-systems are available and worthwhile if you go for dry gloves - they allow air to migrate freely, and make it much easier to get them on and off. However, a dryglove is the most likely place to get a puncture, and if you use a ring system, a leaky glove means a leaking suit.
A good pair of wet gloves is less bulky and less problematic than dry gloves. In extremely cold conditions, 3-finger mitts are the warmest wet gloves you'll get (Thumb, first finger, remaining fingers). Some practice is necessary to maintain dexterity with them though.
Wet gloves can be awkward to put on, especially when wet. Disposable plastic gloves such as are given away at petrol stations makes sliding your hand in effortless. Titanium linings do NOT add any insulating ability, it's pure hype.
I use: Beaver 5mm wetgloves or Poseidon 5mm mitts (With Scubapro Amara gloves underneath for VERY cold conditions)