Which dungeons are easy to solo and give good loot as a rogue?

Sprite world is a fun one to do if you don't have maxed dexterity, cloaking before running into the boss (Limon) will delay his fight starting and allow for some easy hits to start it off. An added bonus to this is the chance of getting Limon's UT cloak drop, the planeswalker, which allows you to teleport as well as cloak. Even further than this, Sprite gods will occasionally be in this dungeon too and will often drop attack potions.

My other suggestion would be UDL (undead lair), this dungeon can be difficult, though cloaking can easily skip the tricky rooms, the boss, Septavius, drops wisdom potions and the doom bow most notably, which makes the dungeon very worthwhile. Rooms to look out for or potentially skip are ones with black and brown slimes in them as these are particularly horrible rooms to traverse.

Sprite world is dropped by Sprite gods (the pink ones) as well as their little stars, whereas UDL is dropped by ghost gods.

Another dungeon to do would be Snake Pit, which drops speed potions. If you have not taken any potions, then you will need to be careful and probably clear every room. I suggest reading up on it here if you aren't familiar with the dungeon. The website includes tips on how to do it and what the dungeon portal drops from, and drops of interest from the dungeon boss. Any lower dungeons don't drop anything good that can be traded, but if you need lower level equipment then you can do them. Lower level dungeons are Spider Den, Forest Maze, Pirate Cave.