The transfer window has finally slammed shut with a number of Premier League clubs making last-gasp signings on the final day. England's top-flight teams have now concluded their summer business, with the next opportunity to tweak their squads only coming in January.Many Premier League sides were not expected to spend heavily in the transfer window due to the lingering financial constraints of the coronavirus pandemic. But that was not the case as the overall spending of the Premier League clubs passed the £1 billion mark during the summer transfer window.Which of them had the best transfer window though? So without further adieu, let's take a look at the:5 Premier League clubs with the best summer transfer window.#5 West Ham UnitedDavid Moyes managed to bolster his squad in the required areasDavid Moyes had to be patient in the transfer window despite West Ham's qualification to the Europa League. But the former Everton manager will no doubt be pleased with the options at his disposal following a late flurry of activity.The most notable signing in the transfer window was the arrival of Kurt Zouma from Premier League rivals Chelsea for £29.8 million, adding much-needed athleticism to the club's defensive options. The club also brought in Nikola Vlasic from CSKA Moscow to add some creativity and goals following the departure of loanee Jesse Lingard.The Hammers were keen to secure a deal for Lingard but found the Manchester United midfielder's price tag prohibitive. Nevertheless, they did manage to bolster their defensive midfield by adding to their Czech contingent with the loan signing of Alex Kral.Thought we’d leave this introduction to our #CzechMates… 🇨🇿🤝 pic.twitter.com/XJ8Y3iJqJs— West Ham United (@WestHam) August 31, 2021The lack of a recognized centre-forward cover for Michael Antonio is a concern, but Moyes will no doubt be happy with the transfer window. Especially considering how they were slow to begin their business in the first place.#4 Aston VillaVilla invested theirJack Grealish money wiselyThe departure of Jack Grealish to Premier League champions Manchester City in the transfer window is a huge blow to Aston Villa. But Dean Smith's side have wasted little time in reinvesting the big bucks received for Jack Grealish into the squad.Villa have grand ambitions after re-solidifying themselves as a Premier League force, and the surprise signing of Danny Ings could definitely become one of the signings of the season. The former Southampton man has been a consistent goalscorer over the past few seasons and will go some way to plugging the gap left behind by Jack Grealish.BREAKING: Aston Villa have announced the signing of Danny Ings from Southampton. Didn’t see that coming, very good bit of business! pic.twitter.com/j7hj3drPRr— Footy Accumulators (@FootyAccums) August 4, 2021Jamaican star Leon Bailey will also be someone to watch out for after finally making the move to the Premier League. Villa also managed to sign Emi Buendia in the transfer window and the 24-year-old looks like a solid purchase and he already has experience playing in the Premier League.Axel Tuanzebe and Ashley Young have also been added to bolster their backline. Villa's squad looks stronger overall despite losing their talisman and it could work in their favor.