Bathroom sealant tape might do it. After a while it can look mucky at the edges, but if you clean diligently it will take a long while before you need to replace it. This pic from ebay: http://www.ebay.co.uk/bhp/bath-sealant-tape

It's available in various widths.

HI -- I think some nice molding tiles would look better than that tape . I don't care for the tape because it looks horrible after a while and it looks cheap .Find a molding tile that matches the top as close as possible . The vanity top should have been scribed to fit against the wall but not sure I see enough top overhang to do that.

You could also look for a quarter round tile deep enough to go there -- is that what you mean by a "molding tile", Lefty? I don't like the look of quarter round in the bathroom, but that's probably just a quirk of mine.

Hmm, makes me wonder if there is a "quarter square" tile. Which is to say, a small square tile strip.

Is that a piece of tile running parallel to the vanity top? If you have drywall or plaster walls they can be feathered to level out even after your vanity has been installed. Had this issue with my daughters vanity and my guys were able to level it looks perfect. Also, less money that a tile black splash and keeping the look we wanted.

We do have drywall, but it has already been tiled over. The vanity top came with one backsplash (for the back only) I didn't want to use it as I preferred the tile look as a backsplash. Now thinking maybe we can take the backsplash and have it cut into two small strips. Still not the clean look I was after, but don't know what else to do. Can't tear out the tile to fix the wall. This photo shows the whole installation. Really hate smooshing in a backsplash.

So sorry. After seeing photos you will have to compromise or undo a lot to fix. Would another vanity top be possible it may be your easiest fix, but not inexpensive. Good luck.

The mirror should be hung higher. Then do a nice backsplash Since it's such a tiny space, it won't be an expensive fix.

This mirror is a built in, going all the way from top to bottom, so that is not an option. thanks for everyone's input, I really appreciate it. Will try and add a trim piece made from the quartz top leftover backsplash. Some of the most simple things turn out to be such a pain. Do not want to introduce another material here.

Well, if you *really* want to keep your tile style the way it is, you could have a new counter templated to your space. A test of priorities. ;)

Is your door jamb notched out for the vanity top or am I seeing things? I know walls are not straight in some homes though. Too bad you can't just straighten it out...I would look for quarter found tile if they make it....the same color as your vanity top or your back tile.

Who did this installation? A professional slab installer would not have cut it this way? Correct? A tile guy may be able to install a pencil molding around the gap.

Erinsean, shouldn't the countertop be notched out for the door jamb?

It was. See first photo. If you notched it any more it would not match the top. The walls were just uneven.

Consider removing the door casing and the top row of tile on the end wall. Skim coat the wall plumb and tight to the counter. Reapply the tile end splash and door casing (using what was removed if salvageable or get replacement). Repaint. It's the only straight forward approach that will keep you happy and not bring up other issues.

Napagal, I've run into a similar issue...ugh? How did you resolve? Would it be possible to see an end-result photo? Thanks

Yes, we solved it. Contractor used a small strip

of rounded ceramic tile

We ended up taking off the strip on the back wall which is shown in the first photo