When living there I have always recommended Hwy 34 up from Loveland. But it really depends on the status of all the roads coming into town since the last weather destruction.
My understanding - from what I have read and info from friends - is that Hwy 34 itself is all re-built to solid asphalt but the edges in some spots are still kinda iffy.
The other option is Hwy 36 thru Boulder or over on the 66 to Lyons and the 36 up. But there was major damage along that way as well and not sure of the status.
Best check it all out with CO DOT.