Cycling Trousers

Endura Urban Stretch Pant is OK for me. Looks like a normal pair of dark trousers and cost about £57. Slightly stretchy, comfortable and not overly hot in the office. There's a softshell version as well.

Bought a couple of pairs of Union34 trousers from Rutland Cycles recently as they were deeply discounted from £99 R.R.P. to £20. DWR coating, concealed cuff cinchers and gusseted - very happy with them as a commute trew. A few sizes left, but size down IMO.

howies do some pretty good stuff.

I've got a couple of pairs of Levis commuters at the moment, they're pretty good.
The 505 indigo jeans (which, really annoyingly, they don't make any more) are great for my build. Slim and slightly tapered, with enough room for bike thighs and a narrow waist.
I've also got some 511 trousers in tan, which do well as that awkward semi-smart trouser if you want em to. Alas the 511 is too narrow for my legs if I size to my waist, so I have to go the size up and cinch them in with a belt - not great for the cut really.
Both have a reinforced gusset that is hard wearing and gives you more mobility than normal jeans, and both have the reflective leg inner seams. In theory they have a nano coating, but in practice it's rubbish. So don't buy them hoping for water resistivity.

I've just taken a punt on a new Kickstarter project - Osloh jeans - so we'll see how they pan out next year.
Other ones on my radar are the Outlier keirin jeans, which are not only really expensive but also cut for actual bike riders - i.e. slim cut with room for your beastly thighs.
Rapha jeans look well made but have that loathsome west london almost bootcut style, so that's definitely not one for me.

Mudguards, normal clothes, rain cape, relaxed pace.

It's just a bike you don't have to dress up to ride it.

Try swrve WWR trousers, got two pairs and they are brilliant. Water beads off them, stretchy, comfortable and can be worn in the office (or pub)