AWhat is the best filling to use with a Lemon cake?

AIt depends on taste really that's a rather broad question. You could do Lemon buttercream, lemon mouse, lemon curd, blueberry, raspberry,coconut, white chocolate. I've done all to favorable review

Almond flavored buttercream is good, too!
 

AI have done all Morganchampagne has done, plus strawberry and blackberry and black raspberry.

I have layered chocolate ganache and raspberry in lemon cake. It is delish!

ACream cheese and blue berry?

Strawberry and raspberry are my favorites with lemon cake. I haven't tried blueberry, but that sounds really good too!

AStrawberry and raspberry are my favourites, too.

I like lime curd and orange curd too.  There are a lot of options.

AI love to mix cream cheese with lemon curd, no additional sugar added. It is so good!

They all sound so good...I would like to add Lemon Bavarian Cream to the list.

AOoo, the lemon Bavarian creme sounds good! Ill have to try it! I may go with a raspberry or strawberry. Just Try to break up the lemon a little bit, so u don't get all lemon! Thanks ladies!