Easy to start out with but requires a little more attention than just fish, is a "softie" tank. Which include mushrooms, leathers, zoanthids, palythoas, and various other non skeleton producing corals.
If you google ridcordia garden or zoanthid garden, you can tell right off the bat that there is some dedication to it, but amazing results will come with it.
FOWLR, or fish only with live rock, tanks, IMO, require the same amount of care, but a different care. For example, you dont have to worry about a zoanthid jumping out of the tank and carpet/counter surfing. In FOWLR tanks, you have to take into account that any fish can do that and what you are willing to do to prevent it. Granted, very few of my fish have jumped, but the few that did, i was upset about.
Then there is the less popular marine planted tank. Which requires again some different dedications and care but still comes out pretty nice if you ask me.
Some other "types" of tanks.
Species specific, NPS (non-photosynthetic), cold water, sea horse/pipefish, mixed reef, maxi-mini garden, anemone etc. Just google image search those names with the word tank after it and see what appeals to you most and we can help you set something up.
Check out on youtube David Saxby's Reef Tank. IMO, one of the greatest reef tanks that is privately owned.