Venus

The second planet from the Sun, Venus is even worse for stuff than Mercury is.  First of all, the gravity is almost the same as on Earth, so that wouldn't be a problem.  Unfortunately, you would still be crushed by 1,322 PSI or 90 atmospheres of pressure at sea level, which is about the same as 900 meters below the surface of the ocean.  Handily, it's very easy to calculate approximate atmosphere pressure in sea water, since pressure in atmospheres is almost one-tenth of depth in meters, but it's not exact, so you can look at this for your pressure calculations: http://www.calctool.org/CALC/other/games/depth_press  Or this to do the calculations yourself: https://www.grc.nasa.gov/www/k-12/WindTunnel/Activities/fluid_pressure.html

It seems that it would be impossible for humans to survive the pressure, but perhaps they could!  An intriguing page talks of exposure of mice to 90 atmospheres of pressure, with survival of the mice.  A couple of google searches later, I found this, however, the link to the PDF appears to be broken.  Then I found out that the article is from Science magazine, in the 5 June 1964 issue.  To download the PDF, you need to be subscribed to Science magazine, which I am not.

This is what happens to a Styrofoam cup at 2300 meters:


Probably the house would collapse from the pressure, but it would be possible to build a habitat that could withstand the pressure, like a research submarine.  Lava flows are the closest to oceans that Venus has, and there's no way that a boat could survive floating on lava.  What would happen to the plane is neatly summed up by What If, and also segues to our next problem:

Your plane would fly pretty well, except it would be on fire the whole time, and then it would stop flying, and then stop being a plane.

The other problem with Venus is the heat.  Its mean surface temperature is 735 K, hot enough to melt lead.  You could survive for a short time in another kind of Fire proximity suit if it weren't for the pressure.

However, above the clouds, they say that Venus is surprisingly like Earth, albeit a Earth with sulfuric acid, unbreathable atmosphere, and category-5 hurricane winds.  It's so much like Earth that NASA has a Venus exploration plan using airships, known as HAVOC (High Altitude Venus Operational Concept):


Conclusion: Venus is hard, but not impossible, as long as you're okay with not going to the surface.