First, I would think it depends on what type of aquarium shape you prefer - cube or rectangle? Second, do you want it to come with a light or not? Third, do you want options for a skimmer or reactor to fit? After all of that, two options initially come to mind (and a third I have never seen firsthand), but only one that is ~5 gallons: Fluval Evo 5 (~$100) - a little to tall and narrow of a footprint for my taste (basically a peninsula type at 20" x 7" x 11"), and not sure I like the light and filtration layout. It also has a partial cover to keep fish in and evaporation down.
The Innovative Marine Nuvo 10 is basically a cube, but I like that one can add either a skimmer or reactor from IM that fits well. Can also get it with or without the light ($100 or $200), but I would get it without and add my own (and a better one such as an AI Prime, Kessil A80, Maxspect Celestial, etc.). Full disclosure - I have one of these in my office and like it a bunch, and I replaced the included screen with a glass piece to cut down on evaporation and keep the fish in.
One other to consider that is newer and different is the 5g (~$73) or 7g (~$84) Lifeguard Aquatics full-view aquarium w/ filter - a unique angled front glass nano that can be had with or without the all-in-one insert at Marine Depot. It also comes with a nice glass top.
Good luck, and report back on what you decide...
