Two things to keep in mind while looking at this list. 1.) ALL of these are Golden Age issues, with the "newest" book coming from 1948. We'll do a second list somewhere down the line of Silver, Bronze, Copper, & Modern Bat Keys.
But let's go ahead and lay the ground work & share all the big first appearances for what has been the # 1 comic book hero since the 1960's.
And # 2, we're not going to do any "2nd appearances." I'm sure any of us would love to have Detective Comics # 28 or Batman # 2, and their value is certainly higher than several of the below issues. But 2nd appearances aren't any fun. So... we know they're there, but we'll leave them on the shelf for this list.
10.) Batman # 4 (December 1940)
Significance: First Mention Of Gotham City
Priced From: As low as $1,100 for a graded 2.0
Creative Team: Bob Kane (Art) & Bill Finger (Story)
9.) Detective Comics # 66 (August 1942)
Significance: 1st Appearance Of Two-Face
Priced From: Relatively affordable at about $3,000 for a serviceable copy.
Creative Team: Bob Kane (Art) & Bill Finger (Story)
8.) Detective Comics # 140 (October 1948)
Significance: 1st Appearance Of The Riddler
Priced From: $8500 will buy you a CGC graded 6.0 currently for sale on EBay.
Creative Team: Dick Sprang (Art) & Bill Finger (Story)
7.) Detective Comics # 40 (June 1940)
Significance: Classic Cover; 1st Joker Cover; 1st Appearance Of Clayface
Priced From: Only one has sold on Ebay in the past few months. So this isn't much of a basis to go by, but it sold for $4,900. This is an incredibly scarce issue, so the price is tough to nail down.
Creative Team: Bob Kane (Art) & Bill Finger (Story)
6.) Detective Comics # 35 (January 1940)
Significance: Classic Hypodermic Needle Cover
Priced From: $23000 for a graded 1.5 Unrestored Copy
Creative Team: Bob Kane (Art) & Bill Finger (Story)
5.) Detective Comics # 58 (December 1941)
Significance: 1st Appearance Of Penguin
Priced From: There is a recent sale of $3800 for a graded 3.0 from December. None currently for sale on the bay.
Creative Team: Bob Kane (Art) & Bill Finger (Story)
4.) Detective Comics # 33 (November 1939)
Significance: 1st Told Origin Of Batman
Priced From : Recent sale of $28,200 earlier this month for a restored CBCS 9.4
Creative Team: Bob Kane & Sheldon Moldoff (Art) ; Bill Finger & Gardner Fox (Story)
3.) Detective Comics # 38 (April 1940)
Significance: 1st Appearance Of Robin
Priced From: If you have $17000-$20000 to spend and would rather buy a comic book than a car, this one may just suit you.
Creative Team: Bob Kane (Art) & Bill Finger (Story)
2.) Batman # 1 (June, 1940)
Significance: First Solo Series; 1st Appearance Of The Joker & Catwoman
Priced From: $15000 gets you into the arena, if you're willing to buy a copy with a back cover missing, or a copy with restoration done to it. But you're going to have to at least double that if you're looking for a decent copy.
Creative Team: Bob Kane (Art) & Bill Finger (Story)
1.) Detective Comics # 27 (May, 1939)
Significance: First Appearance EVER Of Batman
Priced From: Using Ebay, no complete copies for sale, there's one that's not even complete, missing the cover, and honestly looks like it was thrown away, priced at $33,000
Creative Team: Bob Kane (Art) & Bill Finger (Story)
Comments: One of the 2 most expensive books ever published along with Action Comics # 1. Easily one of the holiest, holy grails of all time.