Overall the best bang for your buck is going to multi-tenant cloud based software. You are saving money on infrastructure and not paying any large up front licensing fee. Three choices for manufacuring are NetSuite, Plex, and SAP Business ByDesign. I have connections to all three with a focus on ByDesign. Take a look at demos of ByDesign on my website. Read the articles if you want to know some of the pitfalls of ERP and some of the risks. www.appliedprogress.com
I'd suggest Infor SyteLine ERP as an option- it's been around 25+ years so it's stable and proven, yet has been kept current from a technology perspective - .NET & SQL - http://godlan.com/
Can be on-premise, Cloud, or a hybrid of both - giving you ultimate flexibility to start with non-mission-critical, non-real-time processes on the cloud and keep the rest on-premise. I recently blogged about this and posted a technical paper if it is of interest: http://tinyurl.com/mhjcxwu
We've answered your question as part of our From the Community series. See our top three picks (like IQMS EnterpriseIQ on our Top ERP for Manufacturers of Non-Standard Products post.