1920

First off, I probably should caution you about your adjectives, especially words like "good". For coin collectors, "Good" has a technical definition, and actually means "rather bad"! If it's actually in Good condition, it's only worth a dollar or two at most.

We'd really need to see pics of your actual coin to have a go at estimating a value, but if you can't post a pic, click here to download the ANDA grading guide for George V coins PDF file; compare your coin with the ones pictured and you should be able to give us an approximate measure of condition.

Finally, in 1920 there are five (known) major varieties to look for. They all involve the presence or absence of little tiny dots above and/or below the two little scroll-shapes above ONE and below PENNY, on the reverse. You'll probably need to have a good look with a magnifying glass or loupe or post some high-res pics of the two scroll areas here on the forum to find out what you've got.