Need help with tire selection!!!

I'm looking to replace my tires on my 2009 Cannondale CX-9. Right now I have Maxxis Raze tires, size 700x35. I'm looking to replace them with a tire with less tread, slicks, and they will mainly be used on my rollers for when the weather gets too cold and I wimp out. But I would like the tire to be good enough so when spring comes and there is a pretty desent day and I feel like riding outside, I don't have to change tires. I really don't care if I go down a size or 2, but I really don't want to drop all the way down to 23c. Any help would be great!!!!

I find that 28s are a good compromise between race tires and hybrid tires. A little bit of cushion, but still plenty fast. I had some great 28s by Panaracer (Paselas, maybe) on my last commuter. I have Panaracer UrbanMax tires in 32 on my current commuter, but they may be a little too treaded (inverse tread) for trainer work. Generally speaking, I've been happy with anything by Panaracer- good value for the price.

+1 on the 28s. The first new tire I purchased for my hybrid, my LBS encouraged me to go from a 35 to a 28 in the front. Last week I needed a new tire in the back and switched to a 28 there as well. It's a good compromise as Becky said.

So 28's would be a good tire so my bike. Would they be ok in loose gravel and the occasional gravel road. I also ride alot on chip and seal roads, plus something low tread that I could use on rollers.

I've ridden 23s and 25s on both gravel and chip seal. I wouldn't ride a lot of gravel with them, but they're fine on chip seal. The 25s are definitely more comfy. You should be fine with 28s.

As for trainer work, most 28s should be ok as long as there's not too much tread. The more treaded the tire, the noisier it will be on the trainer. I wouldn't use expensive tires in any size on a trainer- they wear the rear tire down very quickly.