Not sure if brand is more important than comfort and ease of use...
1/4" stuff is great cos it is small and easy to work with for all the smaller fasteners. This is my favourite and very good it is too with the flexi head:
With a 1/4" bit socket (you only need the bits then instead of loads of sockets):
You will need longer allen sockets for doing things like removing the damper from a pair of forks.
And my favourites for exhaust flange nuts:
Also useful for speed (and pretty awesome cos you can push down on the knob):
Of course, 3/8" drive stuff is useful for all the bigger stuff including spark plugs. I really only use 1/2" for front sprocket nuts and tuber rear axles.
As for spanners, the shiny stuff is really nice, but the svelte Stahlwille is really nice to work with:
T Bars are great in use too, as there is nothing to them, you don't need to be concerned with brand. Some examples here (I have the second one plus one similar to the first that takes 1/4" hex bits):http://www.ebay.co.uk/itm/1-4-Inch-Sock ... 5d49edf85chttp://www.ebay.co.uk/itm/T-Bar-1-4-Sq- ... 4ad0b16000
As for allen keys, a set of T bar ones with a ball end are useful (don't go doing stuff up too tight with them) but look for ones with a comfortable handle. I have some Teng ones which I found to be the most comfortable:http://www.ebay.co.uk/itm/Kart-Teng-Too ... 4ad0f7c486
And screwdrivers? I always find myself using a set of Stanley ones that I think I got from B&Q. Choose something comfortable.
Your tools don't need to be Snap On or Halfords professional, but they need to be functional, good fitting and you need to enjoy using them...