Which joint to use....help and ideas please.

[Zeddedhed]

SWIMBO has asked me to make a simple bathroom mirror fronted cabinet - no problem there I thought.
The other bits and pieces in the bathroom are all from AW Oak and feature fairly simple, modern design rules. For instance, most right angle joints are plain butt joints - no visible joinery such as Dovetails or Comb joints, no through tenons.
There are a few quick Sketchup images of approximately what I will be making below.

My question is what method would you choose to make a simple butt joint?
The options I have/am currently considering are:
1. Domino
2. Biscuits
3. Dowel
4. Just glue

I want to avoid using those cam-lock connector things. I know I could use a mitre lock cutter but really want to make sure that the joint looks exactly as drawn, so really don't even want to glue, screw and plug it.

Any ideas?

Here's the piccys.

 

[Ghengis]

i would go biscuits

 

[Phil Pascoe]

1, 2, 3, but not 4.

 

[Scoffy]

Pocket screws may be a simple choice.

 

[marcros]

I would go domino, if you have one. Failing that biscuits or dowels.

 

[Zeddedhed]

Thanks one and all for the advice.
I have a domino, albeit the big beastie. I'm not sure if using an 8mm Domino in 20mm stock is going a bit overboard.
If anyone has any thoughts on this I'd be keen to hear them.
Of course I could always biscuit but the Domino feels more accurate.
Or I could treat myself to the Domino 500