Sorry for delay, was on vacation...
I will edit my original short answer to give more extended answers.

- Original question asks about something similar to MS Access. I believe that MS Access was copied 4th Dimension, old good database from French. Its problems although IMO: pascal language, slow as access, expensive.

- Bento have die just few days ago. FileMaker is similar to Access, although less powerful.

These two products include own db engines and they have own server versions (near to 1000-1500$).   

Other solutions are to use database server as mySQL/PostgreSQL and some GUI Manager app. Some already was mentioned: 
  - mySQL Workbench - works only with mySQL
  - pgAdmin - works only with PostgreSQL
  - Navicat - exists editions for single DB or Premium edition (~500) to all dbs
  - SequelPro - for mySQL only, free
and others.  

Since my first post was about Valentina Studio http://www.valentina-db.com/en/valentina-studio-overview and I was asked to provide more info, here it is. 

- I have found this application in April of 2013. It has totally free edition without limits. Perfect GUI for mySQL, PostgreSQL, SQLite and their own Valentina DB. I am using it up to now and so far all right.

- Was asked about relational support, 1:M, M:1, M:M links. All this present in Valentina Studio for all that dbs. Diagrams can be used in free edition also. 

- But there is no forms as in Access. Guys say they will add forms in nearest months, then this will be FileMaker killer IMO :) We'll see. Because note again, they have own Valentina db engine and Valentina Server, as FileMaker and 4D. 

- I very recommend to check this video introduction http://www.youtube.com/watch?v=1wAd1IrwKAs Notice how perfect are diagrams and Data Editor.