Hellobee Boards

Play kitchen, art easel and chunky crayons like these:
http://www.amazon.com/dp/B0010XCT4G/ref=gl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=Z4L330KK6QPW&coliid=I2JI3RPJ32F1QY

I'm planning to get this mailbox toy for my DS, who will be 18 mo in december:
http://www.amazon.com/gp/product/B002IPGXVA/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

DS is also obsessed with these:
http://www.amazon.com/Fisher-Price-Laugh-Learn-Learning/dp/B004717NNU/ref=pd_sim_t_2?ie=UTF8&refRID=19RH22BJVPFQ3Y0D364A

VTech 2-in-1 Shop and Cook: Playset:
http://www.amazon.com/gp/product/B00CMNX7U8/ref=oh_aui_detailpage_o02_s02?ie=UTF8&psc=1
We have the Vtech walker too, but DD plays with this one a lot more, since she was 13 months. She's now 22 months still plays with it everyday.

Tolo First Friends Farm Quad Bike:
http://www.amazon.com/gp/product/B004SBSI6K/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
DD loves the little boy. You can turn the boys head, hat, move its arms and legs. The car zooms pretty fast by pulling it back and letting go. DD still doesn't quite get that concept yet. She just pushes it forward.

Melissa & Doug Deluxe Classic Peg Puzzle Bundle:
http://www.amazon.com/Melissa-Doug-Deluxe-Classic-Puzzle/dp/B000KWJSKG/ref=sr_1_2?s=toys-and-games&ie=UTF8&qid=1413990658&sr=1-2&keywords=melissa+and+doug+puzzles
DD started really engaging in these puzzles when she was about 15 months, it was her favorite from 15-21 months. She is bored of it now because she has mastered it! I have to say these three puzzles were her stepping stone in learning all her abcs, 123s and colors. When my dad intentionally puts the fish in all the wrong order, she'll re-arrange them correctly and give him a disapproval look haha.

Water Painting Doodle Mat:
http://www.amazon.com/gp/product/B009F7S3A8/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
doodling without the mess.

LeapFrog LeapReader Junior Interactive Letter Factory Flash Cards:
http://www.amazon.com/LeapFrog-LeapReader-Junior-Interactive-Factory/dp/B007U7LZQO/ref=sr_1_9?s=toys-and-games&ie=UTF8&qid=1413991292&sr=1-9&keywords=leap+frog+abc
These also contribute to her abc learning. It is double the fun with the tag junior, when you point it at a card it'll say the letter and sing a song (need to download it via USB).
http://www.amazon.com/LeapFrog-21201-LeapReader-Junior-Book/dp/B005ZCY36K/ref=pd_bxgy_t_text_y

megablocks, art supplies, books, little people sets, melissa and doug puzzles.

Good ideas were already said, but I agree with Megabloks, play kitchen, and aquadoodles My 16 month old daughter loves those right now, and also the Leapfrog picnic basket which I bought for the play food since her play kitchen didn't come with much (hand-me-down), she loves that basket!