Do you realise that “Europe” is not a country, but rather a geographical area consisting of 44 independent nations inhabited by around 750 million people?

Your question is just about as inane as someone asking for a recommendation for “Africa” or “Asia”. Give us a country and the help might be a bit more forthcoming.

And, no, 2.5 year olds will not remember a vacation for very long. It’s perfectly okay to take their needs into account, but that doesn’t need to stretch much further than “do they have high chairs?”.

So without having a clue what you’re after, Hotel Reisen in Stockholm is quite nice. Another option could be Hyatt Regency on Malta, or maybe the Hyatt Regency in Lisbon. Those who are not geographically challenged will have noticed these suggestions are at the opposite corners of Europe, and serves only to illustrate the daftness of the OPs question.