So far, my favorite stamps I have gotten as one who just started in early 2020:
a) 2019 Transcontinental Railroad Stamps
b) 2018 Head of Statue of Freedom ($1, $2 and $5)
c) 2021 Go For Broke Commemorative. The intaglio effect on the stamp is simply NOT captured by photographs. It is cool and the stamp is an excellent example of a simple and beautiful design.
d) 1994 Surrender of Burgoyne - inherited
and one of the most beautiful engraved modern stamps in the collection I was able to salvage.
e) The transportation coil stamps from the late 1980's early 90's - a wonderful series and I only have a few of them. Wish my family had collected all of them.
f) 2019 Postal Murals stamps
g) 2020 American Innovation stamps
h) Grand Ice Caverns Priority Mail Express 2020 stamps - really wonderful artwork of an unusual natural wonder
i) 1988 Carousel Horses Stamps
j) US-Japan join issue 2012 Cherry Blossom stamps
k) The Chippendale 4 cent stamps from the American Design series starting in the early 2000's
l) I love the Butterfly non-machinable stamps and hope to get more of the discontinued ones.
UN - NY stamps
a) All I have are the red flowers and one of Ghandi from 2009 but what a beauty these are.
a) Many of the city and country scenes of Austria engraved and issued about the period of 1974 - 1980
b) Kenya Uganda Tanganyika British Commonwealth during the reign of George VII - enjoy the high quality of the design as well its history
c) 2003 Great Britain Regional stamps - got them recently and again enjoy these
d) From Poland what stamps I have - not much - from the great stamp artist Czeslaw Slania.
e) 2018 Hannukah stamps for Israel (although a joint issue the mint sheets have them in shekels and other identifiers showing these are for Israeli post)
f) All 4 of the Graphic Design stamps from Iceland
As for coin collecting interests:
a) Coin roll hunting to save money and train my eye. It started from searching for W quarters and old silver coinage. Then I started to get into Lincoln cents, anything from after 1976 try for Red redbrown (with red still predominant) in high Au and MS recently put into circulation but still could qualify for MS, from the mid 1960's - 1975 AU or a very high XF with nice strike and red but more likely red-brown, prior to about the 1960's only very modest mintage, scarce, or if very lucky a rare one --- even if very worn like a 1917D I found in a Coinstar
b) Coins I spend money on and my main focus: Walking Liberty Half dollars, Gold $1 (when I can afford a nice one), American Innovation golden dollars, American Silver Eagle - mainly the Burnished Uncs from the West Point mint, British Mandate Palestine coins.
c) Coin I like very much but I get only if I have extra cash - Peace dollars and, more often Franklin halves. The franklins I like since you can get nice Mint state coins for under $50 quite easily (I avoid the whole mania for full bell lines).
d) I have a few enrollments from the US Mint I get every year - not a huge focus but I like to have the current circulating and NIFC coinage. Just one mint set and a proof set (silver or clad depending on budget).
I like to have a variety of areas to collect as my income fluctuates much. I will say that when I tight or flush, I will always go for one or two nice Walking Liberty, save for one $1 Gold (even if it takes a year to pay off!), get at least one or two British Mandate Palestine coins and my US Mint enrollments. This offers me much flexibility and as I like to explore, it offers a core to come back to.