I'm going to call this the interesting/different ships post -- ships that don't conform to the norm.
Let me start with the Norwegian intelligence collection ship FS Eger (formerly Marjata): This has to be one of the most bizarre hull forms I've ever seen. The Eger was designed to operate in the far North targeting operations of the Soviet/Russian Navy there. I suspect she has the full spectrum of intelligence collection equipment: acoustic (sonar), communications, ELINT, telemetry, etc. Not to mention the human eye. The Russians have been rather testy about the Norwegian intell collection ships and complain and harass them. The Norwegians just keep on keeping on.
The Eger is 267 feet long and has a beam at the stern of 131 feet. That's approx the same beam as a U.S. aircraft carrier! She displaces 7,560 tons and is powered by both Diesels and gas turbines, but is not speedy: 15 knots max. I believe the unusual hull form makes the Eger more stable in rough seas. As befits a ship engaging in extended independent operations she has a helo deck for resupply or MEDEVAC.
She was replaced almost 10 years ago by a new intell collection ship which assumed the name Marjata; the new one looks like a small cruise ship but with lots of antennas. (not pictured)
Next up: The Singapore Navy's Formidable class stealth frigates. These are actually not that unusual in the year 2023 as a number of navies have pursued stealth in warship design. Singapore has six of these and they are based on a French frigate design. 377 feet long with a 54 foot beam, they displace 3,200 tons. They are Diesel-powered and have a max speed of 27 knots (31 mph, 50 km/hr.)
Next is the U.S. Navy Zumwalt class destroyers. The original plan was for a large class but huge cost overruns caused the number built to be cut to three. The cost was horrendous, as was the size. These are cruiser-size ships: 610 feet long with an 80 foot beam and a full load displacement of over 14,00 tons. They feature an innovative gas turbine/electric drive. The two shelters forward of the superstructure are for 155mm guns. Unfortunately, the Navy has no ammunition for these guns and so they are effectively useless -- ridiculous!
The Zumwalts feature stealth design and a wave-piercing bow configuration.
The other controversial recent U.S. ship class is the "Littoral Combat Ship" of LCS, which would probably be called a corvette or frigate in any other navy. The LCSs were made in two forms: One is a conventional monohull and I won't cover that here; the other is the Independence class and that is decidedly unconventional: Sort of a monohull with outriggers, making it a semi-trimaran. Both classes of LCS are lightly-equipped, leading to the uncomplimentary moniker of "Little Crappy Ship" in the fleet.
The LCSs were programmed to have various modules (anti-submarine, mine warfare, etc.) added with space reserved for them; unfortunately, the modules have failed to materialize. That leaves these ships with a 57mm gun and little else in the way of armament, although the photos show that the LCS has had a point-defense anti-air missile added above the helo hangar. They do have facilities for both manned and drone helos.
The Independence (LCS 2) class is 414 feet long with a 104 foot beam; it is powered by a Diesel/gas turbine powerplant and is fast: 44 knots (81 km/hr.) Displacement is 3,400 tons.
Next up is the Swedish Navy Visby class missile corvette with stealth features. 239 feet long with a 34 foot beam and rated at 640 tons. The Visbys have a combination Diesel or gas turbine powerplant and can do 35 knots. The shortcoming is a lack of air defense capability but an improved series is on the way that rectifies that shortcoming.
Finally, a do-over from the Taiwan navy post above: The Tuojiang stealth missile corvette is an interesting design. Diesel powering waterjets for 45 knots and armed with Taiwan-designed antiship missiles. 200 feet long with a 48 foot beam and displacing 600 tons.