1) ZAP Zap-a-Gap, a medium CA that allows you to move parts after contact and is also designed as a filler. It is viscous so a drop of it will generally stay where you put it. It's good stuff, dries firm but not instantly.
2) Loctite 401, this is a (virtually) instant CA but will also 'run' by capillary action along any seam. It is ideal for attaching photo etch railings by placing a drop (tiny), positioning the railing and then when set moving along and so forth. When all is in position and you are satisfied put a drop on the end of your needle and 'touch' it to the bottom of the railing and it will run for a certain length very neatly. This is also very good stuff, under all environmental conditions it stays stuck.
Beware though, it is almost instantaneous so I do not recommend it for tiny or even small parts that you have a chance of misaligning because you may destroy them attempting correction. Loctite 401 is an industrial super glue (I get it from work) so may not be available in hobby shops but a modelling CA the equivalent for sale at those places would be, so ask the clerk. 401 is fast enough that I don't use a 'Kicker'.
The only epoxy I use for model building is 3M Scotch-Weld Gray which is a two-pack. It bonds very well with ABS, polystyrene, resin and white metal, sets hard and is strong and will require at least twelve hours to cure which will allow you to ensure the fit and positioning is precise. This is another industrial product so you'll have to go to a hardware store.
I don't use this very often at all but when needed it is very handy and does a permanent job. For the most part Zap-a-Gap or an equivalent CA will cover most requirements.