[Build Help] First time in 5 years, need help replacing my old build.

Hello and thank you for taking your time to read this and maybe help me out. So I'm considering building a new pc since my 5 year old is starting to get on my nerves with crashes and booting problems (again). Back then i also had someone pick out the parts for me but I have no way to reach him anymore so I'm turning to you guys for help, since I keep seeing this sub getting mentioned everywhere.

I'm basically looking for a gaming pc but i don't need top notch best stuff on the market. It should just last me another 4-5 years of comfortable gaming. What would be important to me is that I get my money's worth and that it just runs really smooth (so maybe with a ssd? I really have no idea).

I've got like 500-800€ to spend. My budget is rather flexible actually. If I dont need to spend that much for what I want, that's cool but if I need to stretch it out or chip in another 50 bucks that wouldn't be too much of a problem either as long as it is worth it. I live in Germany btw so that should be considered.

I don't need a cd/dvd-drive and I've got Win7 (I don't really need 8 right?)

If you need any further information I will gladly provide it for you.