Easiest Coin Series To Collect?

Roosies '46 to date are pretty easy and inexpensive. It's a massive set that will take some time so in this sense it isn't "easy' but finding the coins otherwise is easy and you can easily picked them up twenty or thirty at a time at first.

If the set is too easy I strongly recommend that you search for Gems which are usually available at little or no extra cost. Just shop around a little and look for coins with nice solid strikes from new dies and minimal marking. Even the silver issues can be a little tough like this and many of the clads are much tougher. Many people complete the set and then upgrade one coin at a time. Post-1967 issues are more easily found as Gem in the mint sets.

There are several rarities that can be included if you like such as the No-S and No-P dimes. If you like varieties I'd suggest looking at the '68 DDO (neat coin), '69-D/D, and the '71-D/D. There are several minor varieties as well including SMS and Proof issues. The dimes have something for everyone and you can tailor make your set to suit your own interests. A circulated date set could be done for $50 and would keep you busy for days.

If you really want "easy" there are wholesalers who will sell you complete BU sets of coins for as little $75. I've seen War Nickel sets for $20 assembled. BU is more.

The Jefferson nickels.

Besides the 1950 d and 2009 p and d which are easy and relatively cheap to get and possibly the 2024 p and d (if they are indeed a modern key date which are still somewhat easy and cheap to get) the rest are easy to get.

Heck even the War Nickels aka silver nickers from 1942-1945 are easy and inexpensive to get.

I've come to collect most of my coins from bank rolls, and sets that are fairly easily obtainable.

I have two different sets of Jeffersons, an in progress set of Buffalo & Liberty nickels, and currently working on a Lincoln Cent series from 1909-2009, plus the shield cents.

I know this is really about USA coins, but my easiest collection to complete was the "Canadian" Prince Edward Island penny/cent set. I was able to complete two whole sets in a couple days.

Roosevelt dimes, even with the silver ones, seem to be pretty widely recommended to get into for an easy collection.
Any thoughts?
I had considered standard Washington quarters. However, it seems a lot of the earlier silver ones are not too cheap and basically not really easily obtained through circulation/coin roll hunting. Oh, that and the fact that I can't seem to find a Dansco album for standard Washington quarters 1932-1998 ANYWHERE.

Would Roosevelt dimes be recommended over Washington quarters?

jbuck, I actually agree with you. Going over things recently, I noticed how expansive and costly the Washington quarter set is. I mean, that's like 30 years worth of silver coins that are pretty hard to find in circulation. I mean, besides the 1932 dated ones, they aren't really that much. I've seen them go for 8-15 dollars or so. But yeah... For me personally, 8-15 dollars for each coin, for 30 years of coins is a lot of money!

I've kind of been looking into returning to some of what I'd call "roots" of coin collecting and trying to find some series to collect that don't require a ridiculous amount of time going to shows/coin stores to obtain them. I started with searching through nickel rolls to fill out my Jefferson albums, and it was extremely cheap and pleasing. I did purchase some coins as well, though, but found many in circulation, even the older ones.

A few more cheap series to get into it seem would be:
Lincoln Memorial cents
Shield cents
State Quarters
Kennedy half dollars

My Buffalo nickel album is also coming along slowly but surely.
I started out mostly acid dated treated coins in 2x2's. I now am looking for much better examples for my Dansco album.

My Kennedy half dollar set is also fairly inexpensive. I am missing a few of the 1964 silver coins, though. The rest are all clad coins, so it's just a matter of finding them honestly. Sometimes my credit union will have a few loose ones. They never have rolls, though.
I would be interested in adding some of the earlier silver proofs and SMS coins, but not sure how to put them into the mix. I suppose a blank page would work at the end of the album.

I really like Susan B Anthony dollars, and they are by no means a hard set to complete. Obviously, the most expensive coins are the two type 2 proofs from 79 and 81. I currently have the 1981 type 2 proof, but no other proofs so far.