Among small cars, plush and farm animals, lego is a very popular toy for children. One of the advantage of this brand is that they have a wide choice of products (lego with farm animals, zoo animals, fire fighter, ...).
Also some of the lego include a nice little box that is useful to tidy up after play time. Lego products are generally for children who are 2 years old and older but some are also playable by children who are 1 year and a half and some are only available for 3-year-old and older. Just check the box, it is clearly stated (the one in the picture is available for 1 year and a half and older).
2. Stacking Cups
This is a toy children love. I have noticed that you don't need to go for the expensive models. As long as it has colors and can be stacked, your child will like it.
I am linking the one above because it has numbers, but this is not necessary for small children. The only thing I would be careful about is to avoid stacking cups in wood. I have one beautiful set myself but my son cannot play with it because he can hurt himself (wood+edges=not good to smash). Also, I think it is better to have cups that have different size, as children like to "tidy up" by putting small cups in big cups.
This is actually a quite original idea as I don't often see it in toys reviews and yet small children generally love stickers. For small children, I have found this to be the perfect "toy" when travelling as it does not make sound, does not need battery, does not make your child hands dirty, etc... You just need a set of stickers and some blank paper to stick them on. Many sticker books include activities or blank spaces where your child is supposed to set the stickers in. Don't bother with it, generally 2 to 3 year old children don't fully understand those, don't enjoy those, and the main thing is to get them occupied peeling off the stickers and sticking them somewhere else.
Buying those on the internet is not so easy as you cannot see the size and the quality of the stickers (should not be too small or too easy to tear apart, ...) but I have heard positive echo about the Djeco 1000 stickers.
4. Sketcher/Doodler/Magnetic Drawind Board
This toy which had become a bit outdated in the past years is making its comeback. Mainly the add of some magnetic "stampers" made it more attractive and fun to children. For example, the child can now "stamp" some rounds, triangles, stars, ...
Also, the plastic quality has been increased and the toy is not broken anymore after 4-5 swipes. Some of them even have colors though black and white seems to be good enough for children to enjoy this toy.
5. Shape Blocks / Form Fitter
This is my last suggestion and again, a popular toy among children. I would recommend avoiding complex figures, as children have enough difficulties with simple forms like circle, square, triangle...
The one on this photo is an Eichhorn toy. I like the fact that you have several toys in one: shape blocks, of course, but also, an abacus on one side (my son did not use it to calculate, but learned the colors with it), a color/pattern matching side with turning pieces and a top which can be removed with yet another game (move rings following the bars).