At least once year, I update the Most Common LEGO Parts to see which parts are gaining (and losing) popularity over time. Today’s snapshot is based on all of the sets from 2016-2020 which have been released and inventoried so far…

10 parts that caught my attention

Rank	Image	Part ID	Part Name (# Colors)	Notes
1 (+2)		4073	1×1 Plate, Round (47 colors)	This part has risen to the top spot for the first time that I’ve seen. (I suspect that the new LEGO Art sets pushed it to the top position.)
5 (+10)		98138	1×1 Tile, Round (49 colors)	A huge jump of 10 positions, also likely caused by LEGO Art series.
36 (+50)		25269	Tile Round 1 x 1 Quarter (34 colors)	This jump in popularity is certainly caused by the new LEGO Dots series.
111 (+77)		35480	Plate Special 1 x 2 Rounded with 2 Open Studs (15 colors)	This one is easy to explain—it’s a tremendously useful part!
200 (+112)		32607	Plant, Plate 1 x 1 Round with 3 Leaves (8 colors)	This 2018 piece has already been used in 178 different sets!
215 (+136)		36840	Bracket 1 x 1 – 1 x 1 Inverted (9 colors)	The smallest SNOT piece ever created is popular for a good reason.
224 (+363)		49307	Brick Curved 1 x 1 x 2/3 Double Curved Top, No Studs (12 colors)	This tiny part is incredibly versatile, with 63 sets since it was introduced last year.
362 (+172)		37352	Brick Curved 1 x 2 x 1 No Studs (16 colors)	Another 2018 piece with explosive popularity growth.
413 (+266)		41682	Tile Special 2 x 2 with 1 x 2 Vertical Plate (10 colors)	SNOT Elements are often quick to grow in the rankings, like this part which was introduced in 2019 in #10264 Corner Garage.
542 (+806)		37762	Equipment Candle Stick (4 colors)	This 2018 part’s versatility was revealed in two sets we’ve reviewed at Brick Architect which included 28 pieces each: #21052 Dubai Skyline and #10270 Bookshop.

P.S. I also use the updated list to make sure that LEGO Brick Labels collection continues to include labels for all of the most common current parts!