I've seen the Bekant but ultimately it's too small. I need the long side to be 1800mm and I need the short side to be at least 1600mm and have enough room to sit straight onto a second laptop/screen. The Bekant and most corner desks don't have enough space on the shorter 'leg' to have a separate work place set up. I'm constantly alternating between screens and workstations so I need that space. An L shape would be ideal, I have one now but the base is 3 pieces and doesn't fit the best together. I also need really decent cable management, I have 4 computers which all need power/networking etc. Not much to ask for I know!
I've got a very cheap Ikea corner desk, can't find it on the site, on the shorter leg I matched it up to a cheap Ikea table of the same depth and cut it to size I wanted (at 7quid a table, no biggy) and bought some Ikea legs, metal connecting straps to join the desks in my office and it looks pretty good, I went for 2000 x 1600, think it cost me ~50quid for the tops and probably about the same for the legs, I use part of the cut down table one side and part the other side as I needed the extra width for bigger drawers. It looks a lot like JohnG image, but is only 60 deep on the sides. The connecting straps keeps the three tables the same height and stuck together lovely, leaving me freedom with leg placement.
Was a good plan, though I got quite a surprise when I cut into the tables to discover they are mostly cardboard as they feel so solid, I suppose it's obvious really, my proper wood desks are a few hundred quid each if I was to buy them
still works great though.
You could probably do similar with some Ikea trotten table tops, not sure how well I could cut a nice radiused curve or finish the edging in a neat way, on my desk the edging wasn't so important as it butted the other desktops, so some paint touch and black edging tape and you can't see it, that would only be around £100 though. two or three tables in an L would work though and wouldn't be bad to sit at in my opinion sized correctly.
Example trotten tables with some choppy choppy for the radius corner, it could always be a straight 45deg line rather than radiused curve.
I'm not DIY expert mind you so this might be a doddle to some, my corner was not quite a corner due to boxed off pipework in the very corner that the desk had to get around, so I had to get cutting anyway to fit a table in corner and so got brave
part of the reason I stayed cheap, as I have no skills in this area.
jpauls link looks like a good place for custom bits as it has all the right edge bits etc.
In my other office I just have two 120x80 desks in an L shape rather than a specific corner and that gives me work and bench space for books, VR and console crap but only have these due to a office clearance and had them for the price of a pint, I didn't need drawers here, so it was fine and if I was going to sit and use it as a corner desk or screens on both sides one of the desks would need to be longer really by approx 80cm.