Antenna for radio
Using an antenna on the roof of the building it is being used in, instead of an antenna attached to the radio is usually the best way of improving reception.
Don't bother with amplifed antennas for indoor use. An antenna preamp is only usfull for FM when you have more than about 20m of coax between the antenna and the radio.
Added after 6 minutes:
For normal use you need an omnidirectional antenna. FM stations are usually vertical or mixed polarisation.
A dipole is cheap. You could easily make a vertical colinear antenna.
If you want to receive stations from just one transmitter you can use a yagi.