Regular or the hot glue for wood 

strong bond 

i reccomend sanding the area a little before but not necessary.

once cooled/cured it is opaque usually 

Can be messy to apply 

usually creates a small gap where parts are joined. 

Gel helps bond to non flat/smooth surfaces. 

strong bond 

sanding a rough area down a little bit will help make the bond stronger. 

great for tiny parts. 

Dries clear 

sands well (needs mask and ventilation) 

Great Bond 

good for large parts

needs a dremel and bits of PLA filament 

You can sand PLA