Being Canadian, I feel obligated to chime in on this one!
Here's my collection of cold weather (paddling) and sailing gear.
- Neoprene Shorts
- Neoprene Vest
- Neoprene Wetsuit (full legs to ankles, and full arms to wrists)
These are great if the water temperature is cold, but sometimes they are too hot if the air is warm and the water is cold, (like in the spring, and on certain fall days) I end up sweating too much, and need to be very diligent in staying hydrated while on the water.
My favourite pieces are the ones listed below. A dry suit is great, but CRAZY expensive, and if you're in cool, but not COLD situations, these are great options.
- Gill Dinghy Top -- This is a great, low cost sailing jacket that keeps the spray and wind off of you. It seals up nicely around your neck, or opens a bit to help ventilate your body a little bit. It's great. About $100 CDN

-Kokatat Tempest Pant with Socks -- These are great too, they snug up above your waist, and have built in socks, so you can launch your boat without getting wet, and again, they serve the same purpose as the jacket. They keep the spray off, and the wind off. Other then being submersed, the combination of this jacket and top serve as a dry suit for me. About $130 CDN

I combine the above with Neoprene gloves, and Neoprene boots (booties?) that cover the built in socks.
One other thing that I love, that looks a bit ridiculous to my wife, but is GREAT for cold weather is my rubbery on the outside, but soft on the inside, sailing hood (for lack of a better word)

It's about $25 CDN, and is GREAT at keeping your head, and ears warm in the wind. It also takes away all of the wind noise on a windy day, so it's fun to sail with it on, because you hear more of the water, and what's around you, instead of just the wind over your ears.
So don't get me wrong, all of this doesn't replace a dry suit, but even when I capsize my Bravo, I can keep the water out of my pants, and get back to sailing without any problems. You can layer warmer clothes underneath, and I often wear my neoprene shorts and vest (as opposed to the full wetsuit) underneath, to give me a little added warmth.
For me, it's a great combination of comfort vs. cost. The only thing that I might improve on the jacket, (which is available, but costs more) is the ability to have a neoprene snug up option on the bottom of the jacket, similar to the pants. For 95% of what I do, that jacket is fine, but if it snugged up at the bottom, I'd stay drier when I capsize. There are a variety of paddling tops, and dinghy sailing tops that offer this option.
Feel free to ask me any questions if you have any.