The best replacement for shotgun mic is boom mic.

The best alternatives to shotgun mic are rated as following:
★★★★★  boom mic
★★★★  lavalier
★★★  stereo mic

Your alternative for shotgun mic is not listed? Suggest!
Speaking about shotgun mic, one probably shouldn't forget about zoom h4n.

Other search terms related to shotgun mic and their ratings are:
★★★★★ zoom h4n
You have in mind a companion for shotgun mic and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of shotgun mic in all years. Click on graph for more.
shotgun mic
boom mic
lavalier