I'm stuck between learning German or French. I live in the UK and I can get free lessons at my university. Now as an Englishman, it's expected of me to not get along with either, and seeing as we have history with both countries, I'm stuck in the middle for which one to learn so I can verbally grind the denizens of said nation into the ground...

ha crazy right? If I reach old age then I probably will be angry at all the espanol everywhere if I don't learn it by then

Living in San Diego, I would say Spanish. My second language is Tagalog, but I wish I would have learned Spanish also. If you live near any Star Trek conventions, Klingonese would help!

Polish is even more simple in that matter. Aside from several "irregular" words and a handful of two-letter combinations, the pronunciation of the characters doesn't change at all.

How many tenses do we have in our language? Just three - past, present and future, with the future tense sometimes split into simple and complex.

Also, the syntax is quite forgiving. You could change the order of words in sentence, and often it will be still perfectly fine to understand like nothing happened.

One the other hand, there ale five grammatical genders, and countless ways to alter the word, like diminutives, declension, and so on. For example, depending on situation, the number "two" can be pronounced/written.... about 17 different ways.

It certainly isn't. I lived in 70% Latino (almost entirely Mexican) Salinas, California for over ten years and never once had a situation come up that I couldn't make myself understood in English. Every business (even Mexican grocery stores and taquerias), every government office, every doctor's office - every single one had someone who spoke fluent English on staff. I've lived in California my whole life and can remember only once place I had trouble with English and that was a hole-in-the-wall Chinese restaurant in San Francisco. No one there it seemed spoke English (or they feigned ignorance with Chinese just to mess with me).