A few years ago, I watched Nicholas Spark's The Notebook and I noticed a number of similarities between this movie and Titanic that I would like to write it down.

The Notebook

Noah reminds me a lot of Jack, because he comes from a poor family and falls head over heels with Allie on the first day that they met.
The beginning is also very much similar like the beginning of Titanic, because when our 2 characters are old and tells us during their younger days. The same with Rose when she told her story to her granddaughter and the other researchers on the doom luxury ship.
Allie comes from a very rich family and was caught by her parent on her relationship with Noah, they want her to marry a rich man like what Rose's mother did when she set Rose up to marry Cal.
The only different is that Allie broke up with Lon Hammond, while Rose elopes with Jack until his tragic death and that she never see both her mother and Cal ever again while on the RMS Carpathia.
Unfortunately, the music were very underrated compared to Titanic.
Finally, the ending is very straightforward where the couple die holding together on their deathbeds. In Titanic and in my opinion, Rose died and we see her younger version reunites with Jack, as well as those whose lives were perished.

Titanic

This movie has always been in my heart, unlike the Notebook. Titanic is very dramatic and tragic, in which Jack died in the end and poor Rose never got to see him again until the ending.
Lon Hammond is actually a contrast to Cal, the latter wants to marry Rose for his own personal gain. The former is gentle, harmless and friendly, Lon will never marry Allie for his personal gains.
Allie and Rose have a couple of characteristic traits, because they long to breakaway from their overbearing parents. Allie's mother confessed to her that she actually kept the letters that Noah wrote to Allie, while Rose eloped, to which her mother and Cal assumed the worse that she died.

Conclusion

If you happen to watch the Notebook, you will know what I mean on why it is similar to Titanic, enjoy watching it!