If you area a beginner you can try deoriatal I uttarakhand. It is beautiful in winters, I also love the hiking trail which leads to serlosar lake in himachal. For slightly experienced people brrigu lake trek is a good option. The trail is absolutely amazing
If its your first trek go for Deorital chandrashila trek
if you are very fit go for Kedartal Trek as it is hard trek, even try Chandranahan Lake you can try Buranghati from there. Would have suggested Roopkund as i Have done that and nothing is more beautiful thn roopkund but Forest department doesn't allow anymore for Roopkund
(check my profile for Chandrashila and buranghati photos)