I just finished my 1.5 (lm8uu) build, and in the spirit of open source decided to list the important parts I used here.

First, I designed the following two things to be able to raise my MendelMax, so that I could mount the PSU and electronics inside, on an integrated floorboard:

thingiverse.com/thing:28669
thingiverse.com/thing:33612

To protect the PSU from falling debris, aluminum netting used in model building worked really well (awesome stuff btw):

conrad.nl/ce/nl/product/211922/NOCH-60990-Aluminium-gaas/SHOP_AREA_20023&promotionareaSearchDetail=005

Rather than print clips to hide the wiring, I found that electrical tape works well and looks great:

en.wikipedia.org/wiki/Electrical_tape

The following are wonderful x-ends, though they ended up a bit too flexible for my taste (may be my fault, or some parts are just too thin):

thingiverse.com/thing:18384

As for the x and y cars:

thingiverse.com/thing:18657
thingiverse.com/thing:17188

Extruder, also from Jonas Kuehling:

thingiverse.com/thing:18379

It's a bit ugly, but I couldn't find a better method to tension my x belt:

thingiverse.com/thing:13164

My heatbed consists of the following layers:

First, an aluminum plate, because we all like aluminum:

lulzbot.com/products/aluminium-bed-mount-plate

Second, a layer of cartboard wrapped in aluminum foil, to avoid losing heat.

Third, a Prusa heated bed, and fourth, borosilicate glass:

lulzbot.com/products/borosilicate-glass-bed

In combination with my 12V PSU and RAMPS 1.4 electronics, the bed warms up really quickly.

I use springs between the aluminum and the heated bed, to be able to easily level the bed.

Sanded kapton tape and some ABS juice keep my prints very well attached during printing.

As for print head, I used a J-head V. Nice and small.

I ended up using these pretty microswitch holders:

thingiverse.com/thing:28728

As well as this power panel:

thingiverse.com/thing:24053

For lighting, LED strips are great:

buyledstrip.com/en/

update:

I've upgraded the printer in the meantime with precision leadscrews, and disabled z-lifting to avoid z-backlash, and am now getting really nice results at a layer height of about 0.23 mm :

techpaladin.com/store/#ecwid:category=1941327&mode=product&product=8445245

thingiverse.com/derivative:35257

PET sheets also seem to work much better than kapton tape so far (less tears, no seams between pieces of tape, prints seems easier to remove after printing):

lulzbot.com/?q=Pet-Tape-12x12-sheet-green-5-pack