Grove Creek Canyon is located to the east of Pleasant Grove, Utah. It leads you through a somewhat narrow canyon, that eventually connects with the Great Western Trail. Along the way you'll have an amazing view of South Mt. Timpanogos, and pass two waterfalls - the first which is inaccessible, and the 2nd you could probably find a way down to yet wouldn't be easy.
The Tibble Fork Loop Trail (trail #041 & #040) is located in American Fork Canyon, and starts at the Tibble Fork Reservoir, hence the appropriate name. This hike can be done year round, but I find it to be the prettiest during Winter when the trees are laden with snow, the reservoir is frozen over, and the trail offers a certain quietness. The trail steadily gains elevation for the first 2 miles, cuts through an amazing aspen grove and open meadow, then connects back to the Tibble Fork stream and main parking lot.
The Moose Hollow Trail near Jeremy Ranch/Kimball Junction is a lesser known hike that is perfect year-round.
Horsetail Falls is one of my favorite hikes to do with the dogs. I always do this hike in the spring time because I love seeing the spring run off gushing over the falls. This time, I wanted to see it frozen and in snowy conditions. To be honest, I love seeing these falls year round - the views never fail to amaze me. Horsetail Falls is roughly 100 ft high.