Wooden trike, pop up tent/tunnel, stacking cubes, learn and groove table, annoying vtech walker and various bath toys. It's also worth thinking about toys in the 18 month+ age bracket as what they enjoy changes a lot between 1 and 2. Happyland is good from around 18 months plus.
Stacking cups and rings. Vtech walker definitely - still gets used now at 19 months. Simple toy trains and cars. We got DS this percussion set around that time. He loved it and still does. Also a truck for carrying bricks that they can push around.
And books, lots and lots of books. Ones with flaps especially at that stage. We had several of the Usborne Lift and Look ones, like this. There's a whole series of them, they kept DS entertained for ages.
My son is 15 months he loves his ELC magnetic vehicles and has done since he got his first set when he was 6 months old, they come in a pack of three, he has the emergency vehicles, train set, plane set and construction set, he also has the car carrier which comes with two cars, I'd recommend the car carrier the most, it makes sounds.