Anyone have some recommendations for some semi-slicks.

Something I can do adventure races on – so light(ish).

Stans Ravens

Crows are too slick

Bontrager XR1, very fast but nice and grippy, if it's dry.

Panaracer RiBMo's They're super good. You'll love them.

Are the ravens that good? Racing Ralphs are as slick as I'd ever want to go really.

Ravens are good if you can bring yourself to run at the stupid low tyre pressures that Stans recommend which frankly requires some "rearrangement of mental furniture" I could get away with as low as 18 Psi at the back on a 2.2 without problems with burping.
Comparable with XR1's just a bit tougher casing I believe

These;

Love 'em!

WTB Vulpine sl.

high roller SS, well depends how adventurous your planning on being!

panaracer mach ss
very grippy on dry. not mud though

Racing Ralphs. What I've used in AR for years, and you'll also see several other top racers on those. Faster rolling than most proper semi-slick tyres, but with enough grip for real off-road in most conditions. The trouble with running super low pressures is that you'll get a lot of drag on roads and hardpack, something you get a lot of in adventure races, thus making choosing "fast" tyres somewhat pointless.