I love first person grid-based RPGs. I buy almost all that get released for the sake of support, so I've gone through quite a few of them. Some are great, some are good, some are... not so good.
Here's my list of recommendations for those who have developed a taste for gridders, but don't know where to go next. This is by no means a comprehensive list. It includes games I've either played myself, or have been praised a lot by others. I have not included games that are either legally unavailable, or so old that they would be extremely hard to get into for someone who doesn't have that much experience with gridders.
PSP (Vita compatible)
-Elminage: Original. The reviews were very poor because the localization was terrible. The problems were fixed in a later patch, so feel free to ignore the review scores. E:O is actually a terrific Wizardry clone.
-Demon Gaze. It's not out yet, but it's very popular in Japan, and importers like it a lot.
-Etrian Odyssey series. The general consensus is that you can skip the first game. The series is mainly known for the very high difficulty level, but the newer ones are more newbie-friendly.
-Shin Megami Tensei: Strange Journey. I can't say much about this one since I haven't played it, except that it's gotten good reviews and it has a futuristic setting.
-Orcs & Elves. Unlike all the games above, this is not a Wizardry-like. It's much more streamlined, and it doesn't have random encounters (you can see the monsters in the dungeon). A very short, but fun little snack.
-Doom 2 RPG. Made by the same guys as the previous game on the list, so it's very similar. Surprisingly very good.
-Undercroft. Fairly similar to the two games above. Very good, and completely FREE!
-Legend of Grimrock. Not a Wizardry-like but a Dungeon Master-like, which means it has less emphasis on character building and more on puzzles. Real-time combat. If you like these things, this game is highly recommended.
-Lands of Lore: The Throne of Chaos. Like the game above, it's a Dungeon Master clone. An oldie, but still pretty and very easy to get into. Perfect for newbies as well. You can buy this from www.gog.com.
-Might and Magic 3-5. Turn-based combat, no random encounters, open sandbox world. The puzzles come in the form of riddles, not environmental puzzles like in Dungeon Master clones. The emphasis is on exploration. These are very old games, but they have aged surprisingly well and are some of the finest gridders available. Definitely recommended. You can buy the Might and Magic 6-pack, which includes these games, from www.gog.com.
-Might & Magic X: Legacy. This one just came out, and the general consensus seems to be that it's excellent.