Last Night's Television -Unforgiven, ITV1; Million Dollar Traders, BBC2

Here's a tip for any actress hoping to become a leading light of ITV drama: start by pulling or supping pints in the Rovers Return. Following Sarah Lancashire out of Weatherfield and into a spotlight all of her own is Suranne Jones, who was wonderful as sparky, spoilt Karen McDonald in Coronation Street and has done some splendid work since, but nothing better than Unforgiven, a three-part thriller in which she plays Ruth Slater, the daughter of a tenant farmer newly released from prison after serving 15 years for killing two policemen who were overseeing her family's eviction from their remote farmhouse. It is a stunning performance, the stuff of Bafta nominations if ever I saw it. Heck, on the back of it she might even get propelled into the movies, and bring a bit of North Country sense to the Golden Globes.

Speaking of the big screen, that by definition is where an actor's eyes loom largest. If you want to understand the difference between a decent film actor and a great one, watch the eyes, and how subtly they register a flicker of longing here, a flash of regret there. Al Pacino, Meryl Streep, Gene Hackman, Susan Sarandon, they all start with the eyes and work outwards. On television, even in the age of the 52-inch screen, it is a harder trick to pull off. But in Unforgiven Jones does it. She acts principally with her eyes – wounded by her long incarceration, dead to the world of carefree fun – and the rest follows. The words "classy" and "ITV drama" have not always been neighbours these last few years, but Jones is one of the reasons why Unforgiven pulls them firmly together.

Another is the script, written by Sally Wainwright (another Coronation Street alumna). A thriller with revenge and redemption at its heart, seemingly comprising elements of the supernatural, could be a recipe for corn. But Wainwright (probably best known for At Home with the Braithwaites) is a writer of acute intelligence, and she has been well served here by whoever (perhaps it was she) made the casting decisions. Jones leads the line superbly, but Peter Davison, Douglas Hodge and Jemma Redgrave are the most illustrious names in a pitch-perfect supporting cast.

In a nutshell, the plot has Ruth coming out of prison desperate to make contact with her little sister, who was just six when she was sent down for murder, and ended up being adopted by the middle-class Belcombes (Hodge and Redgrave). Living in the house where Ruth committed the murders are another middle-class family, the Ingrams, and John Ingram (Davison), a lawyer, undertakes to help her find the sister. Meanwhile, the sons of one of the murdered policemen are hell-bent on destroying her life as they feel she destroyed theirs. And they know where she lives. There are moments when our credibility is, if not quite strained, then certainly challenged – after being released into the real world, would Ruth have kept the same name and returned to the area where she had earned such notoriety? – but on the whole it is an engrossing, believable story, cleverly and thrillingly told. Five stars all round, and six for Jones.

I wish I could be half as upbeat about Million Dollar Traders, a reality show in which $1m is dished out by "successful businessman" Lex Van Dam between eight aspiring City traders, their brief being to give him a return on his investment. I suppose I might have appreciated it if only I weren't so jaundiced towards the whole stinking world of hedge funds, a world fuelled by greed and testosterone, yet presented here as something beguilingly mysterious, a club really worth joining. As it was, I hated this programme on just about every level, beginning with the name Lex Van Dam, which might have been invented by Barbara Cartland on a bad chiffon day. I hated the plinky-plonk music, which was used in desperation to ratchet up the tension when the stocks went down rather than up, or left instead of right, or whatever it is that stocks do. I hated the careless use of cliches – "the heart of London's Square Mile" – but above all I hated the assumption that we were meant to care about these people and their unhealthy obsession.

Unfortunately for them, they're probably not obsessed enough. A fellow called Anton, supervising them on behalf of Lex, who just called in occasionally like Charlie in Charlie's Angels, berated them for taking half-hour lunch breaks. In eight years, he'd had just two lunches outside the office, he boasted, offering yet another reminder of the mass delusion in the heart of London's square mile that the planet will spin off its axis on the day they stop shouting into telephones.

Still, if Million Dollar Traders was good for nothing else, it at least gave Lex Van Dam the opportunity to offer the following useful advice. He meant it in a trading context but I preferred to interpret it more literally. "Naked punting is for idiots," he raged, and I couldn't agree more.