I won’t say that a joke is inappropriate in a memorial speech, but it must be done with extreme caution.  The worst thing you can do in a eulogy is to offend another mourner.  They will assume you lack respect for the departed and won’t forgive you quickly, if at all.

That being said, depending on who the eulogy is for and the personalities of other family members, I have seen occasions where a well thought out and well timed joke have helped to lift everyone’s spirits.

I tend to recommend poems and quotations, because they seem more heartfelt than jokes.

After the funeral ceremony, when the family is gathered might be a better time.

I have read some decent books on how to write a eulogy, some specializing in eulogies for parents, grandparents, children, etc.  But I’ve never found a book with pre-written memorial speeches that you could put the deceased’s name in and think that you would be honoring them in any way.

There’s a book called A Eulogy to Remember (we offer it here on this site) that has a good explanation of the steps you should take when writing a eulogy, and it does contain thematic outlines, and some sample speeches, but never goes as far as giving you a speech to fill in the blanks.

if you don’t know what to say, or if you are too busy with other funeral preparations to take the time to write a speech that can pay tribute to your loved one, then you should respectfully decline to do the eulogy.