I’ve been writing quite a lot of references for students, mostly for places on MSc degree programmes. The system for supplying these letters has improved markedly in recent years, with most universities allowing PDFs to be uploaded to their web sites. There is variation in user-friendliness however...
Cambridge gets the prize for biggest selection of titles: here is a screen shot:
Exeter is best for country-of-origin selection: most drop-down menus that I use to select a nationality require me the find ‘United Kingdom’ somewhere between Uganda and Uruguay. Exeter’s menu had England right at the top of the list. (Ideally, they would also allow you to select ‘United Kingdom’ so you get to make some kind of political statement via your selection.)
The only annoying ones are those that require you to fill in a Word form on behalf of the student. Luckily there aren’t too many of those (I will not name names).