As with all things SCUBA, depends on what you want to do. There are a lot of good brands out there, but even if you fall in love with Whites, DUI, USIA, Harveys or whatever, you will be confronted with a whole bunch of more important decisions.
Non compressed Neoprene dry suits are very streamlined, fairly durable and insulate to some degree even if flooded. I think O'Neal is still making these. These suits can be repaired easily, but then the seams start to go, they never quite get right again. DUI says they are the only outfit offering Crushed neoprene.
Compressed and/or Crushed Neoprene suites are a little less streamlined, very durable and if you dive in many temperatures of water ,you can collect a whole wardrobe of undergarments. Crushed Neoprene lasts a long time and resists cuts and scrapes, it can be a bit heavy.
Trilam and Shell Dry suits are great, but in general, are the least streamlined. If they flood, they provide no insulation at all. But the are quite durable.
The Fusion is a shell dry suit with a stretchy outer layer aimed as streamlining the suit. Lots of people really appreciate this approach, but it is a more complex system. More parts means more maintenance.
In all cases, you have some other decisions to make regarding
-the profile of your dump valves. Tall valves are inexpensive, low profile valves cost a bit more, both perform well as far as I can tell.
-Installation of a balanced or unbalanced dump valve
-Self Donning/ front entry vs. back entry (shorter zipper, less cost, less to go wrong)
-Socks/over boots, integrated rock boots (I have integrated rock boots but wish I had socks with over boots.)
-Neoprene or Latex wrist/ Neck seals (I prefer latex- it's less comfortable but drier)
-Cone or bottle neck wrist / Neck Seals (I prefer cone, you have a chance of fixing a torn seal with a cone)
-Zip seals or glue on seals (I go with glue on seals)
-Dry gloves or wrist seals (I have wrist seals, never really needed dry gloves even though I dive cold water)
-Custom/ semi custom or off the rack fit (If you buy a suit and then see a tailor, you will want semi custom or custom)
so... there are probably more questions there than answers and few of them revolve around the brand of the dry suit.