The best replacement for azaleas is rhododendrons.

The best alternatives to azaleas are rated as following:
★★★★★  rhododendrons
★  knockout roses
★  encore azaleas
★  rhododendron

Your alternative for azaleas is not listed? Suggest!
Speaking about azaleas, one probably shouldn't forget about hydrangeas.

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



Google Trends

Scale is based on the average worldwide traffic of azaleas in all years. Click on graph for more.
azaleas
rhododendrons
knockout roses