The rain gear I carried and used during LEL:
The North Face Storm Stow jacket
Not cycling specific, but because of its slim cut it is fairly good in the wind (had a Rab jacket previously, the flapping drove me mad). 145 grams and it packs small by cinching off half of the left under arm and using it as a stuff sack. It is a good jacket for touring where you want a decently long jacket with a hood for off-bike use and decent fit for on-bike use. Highly breathable according to TNF (in the real world: just as bad as everything else). Bonus points: canary yellow for added visibility during bad weather. Bought a 2nd one as a spare when I came across one that was 40% discounted. Used it a couple of times during LEL and almost always carry it while riding a brevet not just for rain but also for when temperatures would drop unexpectedly (cold + windchill + mending a tyre = no fun)
The OMM Kamleika pants
It's not tights tight, but a much slimmer cut than all the other waterproof overpants I have seen. Material is slightly elastic. Zippers at the ankles are long enough to allow putting on/off these pants without removing your shoes. I think I used it twice, at night/very early morning when it was fairly cold. Like the rain jacket I almost always carry these on brevets.
Bioracer neoprene overshoes
The nice thing of these overshoes is that they have a close fitting rubber collar around your leg, so water does not flow from your legs into your shoes when you're not wearing the overpants. The bad thing is that you need to remove your shoes to put them on, so it's not something you would do on the road while it starts raining. I'd say I had these over my shoes about 50% of the time, I did ride quite a bit through the night (and there's nothing worse for my than cycling with cold feet).
waterproof mitts with merino liners
The combination keeps your hands more comfortable when it's cold(er) and raining than regular gloves IMO. Also works well on long descends in the alps to keep your hands from freezing. I don't use padded cycling gloves and when things were a bit chilly during LEL I used the liners without the mittens. The mittens I have from Mountain Laurel Designs are made from (*cough* breathable *cough*) eVent fabric, but they are annoyingly large. I wish someone would make a "lobster type" mitten from just waterproof material with a proper fit. Regardless, used the mittens when I used the rain pants during LEL. Merino liners are always with me during brevets (yes, even in summer)
long mudguards / flap
Probably preaching to the choir, but mudguards keep you (the shoes esp.) much dryer and cleaner. Not to mention the chain on your bike.
a positive attitude
It's only water, you know?
