Turner Prize 2008, Tate Britain, London

A really smashing afternoon tea and a walk around the workshop are the outstanding images this year

October again, and with it the annual frenzy of entrail-throwing that is the Turner Prize. What, O gods, can this year's choice portend? And, as with every other year, the answer to that is, nothing. The Turner rewards artists – average age this time, 42 – for having made it, not for being about to. It is awarded by five judges who sit at the art world's dark heart. And do these judges play favourites? Tsk, reader, and tsk again.

And so to the runes. Perhaps the most significant feature of the 2008 Turner Prize is its three-to-one breakdown, a thing unknown since 1998. There is a trio of brunettes on this year's shortlist and one sole blond, he being Mark Leckey.

Perhaps it is a fear of hairism that makes Leckey so difficult an artist. Blond he may be, but dumb he is not; perhaps not dumb enough. There is a kind of conceptual work so very cerebral that it makes your head hurt, and Leckey's is it. As with a good martini, it is not enough for art to be dry. There must, if only a dash, be something else as well: humanity, say, as with Martin Creed, or wit. Leckey's take on cartoon animals – Felix the Cat, a Jeff Koons rabbit – defines itself by not being all the things those animals are: open, engaging, funny. What we are left with is work that is closed, alienating and very serious, on which three grounds, blond or no, I'd like Leckey not to win.

Of course, grimness is not the preserve of the fair-haired. Cathy Wilkes, one of the black/brown trio, also makes work that tends towards the heavy-handed. Her single piece in the prize is an installation called I Give You All My Money, comprising a pair of supermarket checkouts dotted with dirty dishes. Next to these are two female shop dummies, one with a cage on its head, the other sitting on the lav.

Wilkes may have been looking at Surrealism through the distorting lens of Louise Bourgeois, although Bourgeois' vampiric drollery has gone missing along the way. What remains is an agitproppy piece of old-fashioned feminism, none the worse for that although unlikely to rev your engine. On the floor beside Wilkes's tills is a plastic ping-pong bat. The hopeful message of this is presumably "I am playful!", although in truth the work is about as ludic as a Dr Scholl sandal.

Goshka Macuga does at least have subtlety on her side and, as with Wilkes, there's a feminist whiff. Her work in this show reclaims the lesser-known female partners of Paul Nash and Mies van der Rohe, being respectively Eileen Agar and the designer Lilly Reich. A trawl through the Tate archives has resulted in a series of composite Agar/Nash collages, while the steel-and-glass Haus der Frau pieces re-create Reich's displays for a 1929 expo.

The resultant game of mirrors – curating-art about art-curating – is deeply clever, although it may be easier to get it if, like Macuga, you did an MA at Goldsmiths. If not, you may come away with the gloomy sense of having seen a Sphinx without a riddle, or at least one worth answering.

Which leaves us with the work of the artist who is unarguably the one to whom the 2008 Turner Prize should go. Runa Islam makes films about their own deftness, and she knows and loves all the tricks of her medium. Personally, I'd have kept her works in this show down to two, Be the First to See What You See As You See It and CINEMATOGRAPHY.

The first features a murderous woman, shot in saturated colour, who takes afternoon tea off Fifties china before smashing it. The second leads us on a wordless tour of a workshop or garage, all lathes and axle grease. I hesitate to use terms such as "the genderisation of seeing", but that, brilliantly, is what these works are about. Be the First has the porcelain finish of saucers, CINEMATOGRAPHY the muscular, camera-as-eye feel of Tarantino. And yet both leave us with the vague but irrepressible sense that simple answers are never simple.

Tate Britain, London SW1 (020-7887 8888), to 18 Jan 2009