Compared to some other emulators, such as MAME, Amiga emulation hasn't enjoyed as many successful frontends over the years, but there have been a few good ones.
Out of these I would say the most famous two specifically for the Amiga and WinUAE have to be:
Lemonade - From the creators of the Lemon Amiga site.
GameBaseAMI - using the GameBase front end system.
In addition to these there are a few universal front ends that can be customised to work with WinUAE.
MAMEWAH - While that one isn't specifically for the Amiga, it can be easily customised to navigate your Amiga games archive and launch the emulator. It is very lightweight and designed to run from a commandline so you can boot straight to it without needed to first boot Windows fully. Although these days it is a lot of work to get running compared to other frontends.
GameEx - This is a more recent frontend system that is designed to look like the Windows media center. It does look great and works well, but doesn't directly support the Amiga. It also needs quite a recent PC to work well as it is quite resource hungry to work smoothly without slowdown.
There are many other universal front ends, but most have not been updated for some time now, mostly years, so in my view they are now dead and unsupported.
And for the future I look forward to seeing what MAGE has to offer once it gets released. This is aimed at being the successor to GameBase so hopefully it will be great. But only time will tell.
So which Frontend is your current favourite? And what Frontends have you tried?