I am quite (quite, indeed) late on this one. A "good" journal which has probably gone unnoticed (didn't see any references in the answers provided) is the [Milan Journal of Mathematics][1]. Aims and scope:

> Milan Journal of Mathematics (MJM) publishes high quality articles from all areas of Mathematics and the Mathematical Sciences. The authors are invited to submit "articles with background", presenting a problem of current research with its history and its developments, the current state and possible future directions. The presentation should render the article of interest to a wider audience than just specialists.

I remembered seeing an expository article of Heineken on complete groups published in its predecessor, Rendiconti del Seminario Matemàtico e Fisico di Milano. That is quite old though and I haven't recently perused Milan's contents to know if
it indeed does what it claims.

  [1]: http://www.springer.com/birkhauser/mathematics/journal/32