Best indoor FM antenna, your experience.

Whatjd- I have a 2.5 story colonial w a slate roof, so there was no way I was going out on the roof.  What I did was mount a conventional outdoor antenna upside down in my attic so that the elements of the antenna are closer to the floor where it is wider, and the rotor and mast are secured to a tie that extends between the rafters where the attic is narrower. Then I ran the antenna wire out through the attic gable end window and back inside where my tuner is.  You can also try the ST-2 in either Omni (vertical) mode or if the stations are all in the same direction in directional (horizontal) mode.  

Unless you are in an urban area w lots of high-rise buildings, the main issues are height and directionality. So get your antenna as high as possible and have some means of orienting/re-orienting it to get the best reception for different stations. If you in a city w lots of tall buildings, multi-path can make getting good reception hit or miss at best, impossible at worst.